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Full text of "Cosmos : a sketch of a physical description of the universe"

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NEW YORK , HARPER & R ROl H E RS . I 8bO . 



COSMOS: 



A SKETCH 



OP 



A PHYSICAL DESCRIPTION OF THE UNIVERSE. 



BY 



ALEXANDER VON HUMBOLDT. 



TRANSLATED FROM THE GERMAN, 

BY E. a OTTE. 



MatarsB vero rerura vis atque majestas in omnibus momentis fide caret, si qiiia modo 
partes ejus ac non totara complectatur animo. — Plin., Hist. Nat., lib. viL, c. 1. 



IN TWO VOLUMES. 

VOL. L 



NEW YORK: 

HARPER & BROTHERS, PUBLISHERS 

329 & 331 PEARL STREET, 
FRANKLIN SQUARE. 

18 56. 



TRANSLATOR'S PREFACE. 



I CAN not more appropriately introduce the Cosmos than 
by presenting a brief sketch of the life of its illustrious au- 
thor.* While the name of Alexander von Humboldt is fa- 
miliar to every one, few, perhaps, are aware of the peculiar 
circumstances of his scientific career and of the extent of his 
labors in almost every department of physical knowledge. He 
was bom on the 14th of September, 1769, and is, therefore, 
now in his 80th year. After going through the ordinary 
course of education at Gottingen, and having made a rapid 
tour through Holland, England, and France, he became a pu- 
pil of Werner at the mining school of Freyburg, and in his 
21st year published an "Essay on the Basalts of the Rhine." 
Though he soon became officially connected with the mining 
corps, he was enabled to continue his excursions in foreign 
comitries, for, during the six or seven years succeeding the 
publication of his first essay, he seems to have visited Austria, 
Switzerland, Italy, and France. His attention to mining did 
not, however, prevent him from devoting his attention to oth- 
er scientific pursuits, among which botany and the then re- 
cent discovery of galvanism may be especially noticed. Bot- 
any, indeed, we know from his own authority, occupied him 
almost exclusively for some years ; but even at this time he 
was practicing the use of those astronomical and physical in- 
struments which he afterward turned to so singularly excel- 
lent an account. 

The political disturbances of the civilized world at the close 

* For the following remarks I am mainly indebted to the articles on 
the Cosmos in the two leading Quarterly Reviews. 



iv translator's preface. 

of the last century prevented our author from carrying out 
various plans of foreign travel which he had contemplated, 
and detained him an unwilling prisoner in Europe. In the 
year 1799 he went to Spain, with the hope of entering Africa 
from Cadiz, but the unexpected patronage which he received 
at the court of Madrid led to a great alteration in his plans, 
and decided him to proceed directly to the Spanish posses- 
sions in America, " and there gratify the longings for foreign 
adventure, and the scenery of the tropics, which had haunted 
him from boyhood, but had all along been turned in the dia- 
metrically opposite direction of Asia." After encountering 
various risks of capture, he succeeded in reaching America, 
and from 1799 to 1804 prosecuted there extensive researches 
in the physical geography of the New World, which have in- 
delibly stamped his name in the undying records of science. 

Excepting an excursion to Naples with Gay-Lussac and 
Von Buch in 1805 (the year after his return from America), 
the succeeding twenty years of his life were spent in Paris, and 
were almost exclusively employed in editing the results of his 
American journey. In order to bring these results before the 
world in a manner worthy of their importance, he commenced 
a series of gigantic publications in almost every branch of 
science on which he had instituted observations. In 1817, 
after twelve years of incessant toil, four fifths were completed, 
and an ordinary copy of the part then in print cost considera- 
bly more than one hundred pounds sterling. Smce that time 
the publication has gone on more slowly, and even now, after 
the lapse of nearly half a century, it remains, and probably 
ever will remain, incomplete. 

In the year 1828, when the greatest portion of his literary 
labor had been accomplished, he undertook a scientific journey 
to Siberia, under the special protection of the Russian govern- 
ment. In this journey — a journey for which he had prepared 
himself by a course of study unparalleled in the history of 
travel — he was accompanied by two companions hardly less 
distinguished than himself, Ehrenberg and Gustav Rose, and 



translator's preface. v 

the results obtained during their expedition are recorded by 
our author in his Frag?nents Asiatiques, and in his Asie 
Ce7itrale, and by Rose in his Reise nach dem Oural. If the 
Asie Centrale had been his only work, constituting, as it 
does, an epitome of all the knowledge acquired by himself and 
by former travelers on the physical geography of Northern 
and Central Asia, that work alone would have sufficed to 
form a reputation of the highest order. 

I proceed to offer a few remarks on the work of which I 
now present a new translation to the English pubHc, a work 
intended by its author " to embrace a summary of physical 
knowledge, as connected with a delineation of the material 
universe." 

The idea of such a physical description of the universe had, 
it appears, been present to his mind from a very early epoch. 
It was a work which he felt he must accomplish, and he de- 
voted almost a lifetime to the accumulation of materials for 
it. For almost half a century it had occupied his thoughts ; 
and at length, in the evening of life, he felt himself rich 
enough in the accumulation of thought, travel, reading, and 
experimental research, to reduce into form and reaUty the 
undefined vision that has so long floated before him. The 
w;ork, when completed, wiU form three volumes. The first 
volume comprises a sketch of all that is at present Imown of 
the physical phenomena of the universe ; the second compre- 
hends two distinct parts, the first of which treats of the in- 
citements to the study of nature, afforded in descriptive poet- 
ry, landscape painting, and the cultivation of exotic plants ; 
while the second and larger part enters into the consideration 
of the different epochs in the progress of discovery and of the 
corresponding stages of advance in human civilization. The 
third volume, the publication of which, as M. Humboldt him- 
self informs me in a letter addressed to my learned friend and 
publisher, Mr. H. G. Bohn, " has been somewhat delayed, 
owing to the present state of public affairs, will comprise the 
special and scientific development of the s;reat Picture of Na- 



vi translator's preface. 

ture." Each of the three parts of the Cosmos is therefore, to 
a certain extent, distinct in its object, and may be considered 
complete in itself. We can not better terminate this brief 
notice than in the words of one of the most eminent philos 
ophers of our own country, that, " should the conclusion cor- 
respond (as we doubt not) with these beginnings, a work will 
have been accomplished every way worthy of the author's 
fame, and a crowning laurel added to that wreath with which 
Europe will always delight to surround the name of Alexan 
der von Humboldt." 

In venturing to appear before the English public as the in- 
terpreter of " the great ivork of our age,^'^ I have been en- 
couraged by the assistance of many kind literary and scientific 
friends, and I gladly avail myself of this opportunity of ex- 
pressing my deep obligations to Mr. Brooke, Dr. Day, Pro 
fessor Edward Forbes, Mr. Hind, Mr. Glaisher, Dr. Percy, and 
Mr. Ronalds, for the valuable aid they have afforded me. 

It would be scarcely right to conclude these remarks with- 
out a reference to the translations that have preceded mine. 
The translation executed by Mrs. Sabine is singularly accu- 
rate and elegant. The other translation is remarkable for 
the opposite qualities, and may therefore be passed over in si- 
lence. The present volumes differ from those of Mrs. Sabine 
in having all the foreign measures converted into correspond- 
ing English terms, in being published at considerably less 
than one third of the price, and in being a translation of the 
entire work, for I have not conceived myself justified in omit- 
ting passages, sometimes amounting to pages, simply because 
they might be deemed slightly obnoxious to our national prej- 
udices. 

* The expression applied to the Cosmos by the learned Bunsen, in 
his late Report on Ethnology, in the Report of the British Association 
for 1847, p. 265. 



AUTHOR'S PREFACE. 



In the late evening of an active life I offer to the German 
public a work, whose undefined image has floated before my 
mind for almost half a century. I have frequently looked 
upon its completion as impracticable, but as often as I have 
been disposed to relinquish the undertaking, I have again — 
although perhaps imprudently — resumed the task. This work 
I now present to my cotemporaries with a diffidence inspired 
by a just mistrust of my own powers, while I would willingly 
forget that writings long expected are usually received mth 
less indulgence. 

Although the outward relations of life, and an irresistible 
impulse toward knowledge of various kinds, have led me to 
occupy myself for many years — and apparently exclusively — 
with separate branches of science, as, for instance, with de- 
scriptive botany, geognosy, chemistry, astronomical determin- 
ations of position, and terrestrial magnetism, in order that I 
might the better prepare myself for the extensive travels in 
which I was desirous of engaging, the actual object of my 
studies has nevertheless been of a higher character. The 
principal impulse by which I was directed was the earnest 
endeavor to comprehend the phenomena of physical objects in 
their general connection, and to represent nature as one great 
whole, moved and animated by internal forces. My inter 
course with highly-gifted men early led me to discover that, 
without an earnest striving to attain to a knowledge of special 
branches of study, all attempts to give a grand and general 
view of the universe would be nothing more than a vain illu- 
sion. These special departments in the great domain of nat- 



v'lii author's preface. 



iiral science are, moreover, capable of being reciprocally fruc- 
tified by means of the appropriative forces by which they are 
endowed. Descriptive botany, no longer confined to the nar- 
row circle of the determination of genera and species, leads 
the observer who traverses distant lands and lofty mountains 
to the study of the geographical distribution of plants over the 
earth's surface, according to distance from the equator and ver- 
tical elevation above the sea. It is further necessary to in- 
vestigate the laws which regulate the differences of tempera- 
ture and climate, and the meteorological processes of the at- 
mosphere, before we can hope to explain the involved causes 
of vegetable distribution ; and it is thus that the observer who 
earnestly pursues the path of knowledge is led from one class 
of phenomena to another, by means of the mutual dependence 
and connection existing between them. 

I have enjoyed an advantage which few scientific travelers 
have shared to an equal extent, viz., that of having seen not 
only littoral districts, such as are alone visited by the majority 
of those who take part in voyages of circumnavigation, but 
also those portions of the interior of two vast continents which 
present the most striking contrasts manifested in the Alpine 
tropical landscapes of South America, and the dreary wastes 
of the steppes in Northern Asia. Travels, undertaken in dis- 
tricts such as these, could not fail to encourage the natural 
tendency of my mind toward a generalization of views, and to 
encourage me to attempt, m a special work, to treat of the 
knowledge which we at present possess, regarding the sidereal 
and terrestrial phenomena of the Cosmos in their empirical 
relations. The hitherto undefined idea of a physical geog- 
raphy has thus, by an extended and perhaps too boldly imag- 
ined a plan, been comprehended under the idea of a physical 
description of the universe, embracing all created things in the 
regions of space and in the earth. 

The very abundance of the materials which are presented 
to the mind for arrangement and definition, necessarily impart 
uo inconsiderable difficulties in the choice of the form utidev 



AUTHOR S PREFACE. * IX 

which such a work must be presented, if it would aspire to 
the honor of being regarded as a Hterary composition. De- 
scriptions of nature ought not to be deficient in a tone of life- 
like truthfulness, while the mere enumeration of a series of 
general results is productive of a no less wearying impression 
than the elaborate accumulation of the individual data of ob- 
servation, i scarcely venture to hope that I have succeeded 
in satisfying these various requirements of composition, or that 
I have myself avoided the shoals and breakers which I have 
known how to indicate to others. My faint hope of success 
rests upon the special indulgence which the German public 
have hestowed upon a small work bearing the title of Ansich- 
ten der Natur, which I pubhshed soon after my return from 
Mexico. This work treats, under general points of view, of 
separate branches of physical geography (such as the forms of 
vegetation, g;rassy plains, and deserts). The efiect produced 
by this small volimie has doubtlessly been more powerfully 
manifested in the influence it has exercised on the sensitive 
minds of the young, whose imaginative faculties are so strong- 
ly manifested, than by means of any thing which it could it- 
self impart. In the work on the Cosmos on which I am now 
engaged, I have endeavored to show, as in that entitled An- 
sichten der Natur, that a certain degree of scientific com- 
pleteness in the treatment of individual facts is not wholly 
incompatible with a picturesque animation of style. 

Since public lectures seemed to me to present an easy and 
efficient means of testing the more or less successful manner 
of connecting together the detached branches of any one sci- 
ence, I undertook, for many months consecutively, first in the 
French language, at Paris, and afterward in my own native 
German, at Berhn (almost simultaneously at two different 
places of assembly), to deUver a course of lectures on the phys- 
ical description of the universe, according to my conception 
of the science. My lectures were given extemporaneously, 
both in French and German, and without the aid of written 
notes, nor have I, in any way, made use, in the present work, 



author's preface. 



of those portioiis of my discourses which have been preserved 
by the industry of certain attentive auditors. V/ith the ex- 
ception of the first forty pages, the whole of the present work 
was written, for the first time, in the years 1843 and 1844. 

A character of unity, freshness, and animation must, I 
think, be derived from an association with some definite 
epoch, where the object of the writer is to delineate the pres- 
ent condition of knowledge and opinions. Since the addi- 
tions constantly made to the latter give rise to fundamental 
changes in pre-existing views, my lectures and the Cosmos 
have nothing in common beyond the succession in which the 
various facts are treated. The first portion of my work con 
tains introductory considerations regarding the diversity in 
the degrees of enjoyment to be derived from nature, and the 
knowledge of the laws by which the universe is governed ; it 
also considers the limitation and scientific mode of treatinjr a 
physical description of the universe, and gives a general pic- 
ture of nature which contains a view of all the phenomena 
comprised in the Cosmos. 

This general picture of nature, which embraces within its 
wide scope the remotest nebulous spots, and the revolving 
double stars in the regions of space, no less than the telluric 
phenomena included under the department of the geography 
of organic forms (such as plants, animals, and races of men), 
comprises all that I deem most specially important vdth re- 
gard to the connection existing between generalities and spe- 
cialities, while it moreover exemplifies, by the form and style 
of the composition, the mode of treatment pursued in the se- 
lection of the results obtained from experimental knowledge. 
The two succeeding volumes will contain a consideration of 
the particular means of incitement toward the study of na- 
ture (consisting in animated delineations, landscape painting, 
and the arrangement and cultivation of exotic vegetable 
forms), of the history of the contemplation of the universe, or 
the gradual development of the reciprocal action of natural 
forces constituting one natural whole ; and, lastly, of the spe- 



AUTHOR ^^ PREFACE-. XI 

cial branches of the several departments of scienet, whose 
mutual connection is indicated in the beginning of the work. 
Wherever it has been possible to do so, I have adduced the au- 
thorities from whence I derived my facts, with a view of afibrd- 
ing testimony both to the accuracy of my statements and to the 
value of the observations to which reference was made. In 
those instances where I have quoted from my own writings 
(the facts contained in which being, from their very nature, scat- 
tered through different portions of my works), I have always 
referred to the original editions, owing to the importance of 
accuracy with regard to numerical relations, and to my own 
distrust of the care and correctness of translators. In the few 
cases where I have extracted short passages from the works 
of my friends, I have indicated them by marks of quotation ; 
and, in imitation of the practice of the ancients, I have inva- 
riably preferred the repetition of the same words to any arbi- 
ti'ary substitution of my own paraphrases. The much-con- 
tested question of priority of claim to a first discovery, which 
it is so dangerous to treat of in a work of this uncontroversial 
kind, has rarely been touched upon. Where I have occasion- 
ally referred to classical antiquity, and to that happy period 
of transition which has rendered the sixteenth and seventeenth 
centuries so celebrated, owing to the great geographical dis- 
coveries by which the age was characterized, I have been sim- 
ply led to adopt this mode of treatment, from the desire we 
experience from time to time, when considering the general 
views of nature, to escape from the circle of more strictly dog- 
matical modern opinions, and enter the free and fanciful do- 
main of earlier presentiments. 

It has frequently been regarded as a subject of discouraging 
consideration, that while purely literary products of intellect 
ual activity are rooted in the depths of feeling, and interwoven 
with the creative force of imagination, all works treating of 
empirical knowledge, and of the connection of natural phe- 
nomena and physical laws, are subject to the most marked 
modifications of form in the lapse of short periods of time, both 



xii author's preface. 



by the improvement in the instruments used, and by the con- 
sequent expansion of the field of view opened to rational ob- 
servation, and that those scientific works which have, to use 
a common expression, become mitiquated by the acquisition 
of new funds of knowledge, are thus continually being con- 
signed to oblivion as unreadable. However discouraging such 
a prospect must be, no one who is animated by a genuine love 
of nature, and by a sense of the dignity attached to its study, 
can view with regret any thing which promises future addi- 
tions and a greater degree of perfection to general knowledge. 
Many important branches of knowledge have been based upon 
a solid foundation which will not easily be shaken, both as re- 
gards the phenomena in the regions of space and on the earth ; 
while there are other portions of science in which general 
views will undoubtedly take the place of merely special ; 
where new forces will be discovered and new substances will 
be made known, and where those which are now considered 
as simple will be decomposed. I would, therefore, venture to 
hope that an attempt to delineate nature in all its vivid ani- 
mation and exalted grandeur, and to trace the stahle amid the 
vacillating, ever-recurring alternation of physical metamorph- 
oses, will not be wholly disregarded even at a future age. 
PoUdam, Nov., 1844. 



CONTENTS OF VOL. I. 



Page 

The Translator's Preface iii 

The Author's Preface vii 

Summary xv 

INTRODUCTION. 

The Results of the Study of Physical Phenomena 23 

The different Epochs of the Contemplation of the external World. 24 
The different Degrees of Enjoyment presented by the Contempla- 
tion of Nature 25 

Instances of this Species of Enjoyment 26 

Means by which it is induced 26 

The Elevations and climatic Relations of many of the most cele- 
brated Mountains in the World, considered with Reference to the 

Effect produced on the Mind of the Observer 27-33 

The Impressions awakened by the Aspect of tropical Regions ... 34 
The more accurate Knowledge of the Physical Forces of the Uni- 
verse, acquired by the Inhabitants of a small Section of the tem- 
perate Zone 36 

The earliest Dawn of the Science of the Cosmos 36 

The Difficulties that opposed the Progress of Inquiry 37 

Consideration of the Effect produced on the Mind by the Observa- 
tion of Nature, and the Fear entertained by some of its injurious 

Influence 40 

Illustrations of the Manner in which many recent Discoveries have 
tended to Remove the groundless Fears entertained regarding 

the Agency of certain Natural Phenomena 43 

The Amount of Scientific Knowledge required to enter on the 

Consideration of Physical Phenomena 47 

The Object held in View by the present Work 49 

The Nature of the Study of the Cosmos 50 

The special Requirements of the present Age 53 

Limits and Method of Exposition of the Physical Description of the 

Universe 56 

Considerations on the terms Physiology and Physics 58 

Physical Geography 59 

Celestial Phenomena 63 

The Natural Philosophy of the Ancients directed more to Celestial 

than to Terrestrial Phenomena 65 

The able Treatises of Varenius and Carl Ritter 66, 61 

Signification of the Word Cosmos .-. . 68—70 

The Domain embraced by Cosmography 71 

Empiricism and Experiments 74 

The Process of Reason and Induction 77 



XIV CONTENTS. 

GENERAL REVIEW OF NATIJRAL PHENOMENA. 

Connection betweei^ the Material and the Ideal World 80 

Delineation of Nature 82 

Celestial Phenomena 83 

Sidereal Systems 89 

Planetary Systems 90 

Comets 99 

Aerolites Ill 

Zodiacal Light 137 

Translatory Motion of the Solar System 145 

The Milky Way 150 

Starless Open'ngs 152 

Terrestrial Phenomena 154 

Geographical Distribution 161 

Fio-ure of the Earth 163 

Density of the Earth 169 

Internal Heat of the Earth 172 

Mean Temperature of the Earth 175 

Terrestrial Magnetism 177 

Magnetism 183 

Aurora Borealis 193 

Geoo-nostic Phenomena 202 

Earthquakes 204 

Gaseous Emanations , 217 

Hot Springs 221 

Salses 224 

Volcanoes 227 

Rocks 247 

PalfEontology 270 

Geognostic Periods 286 

Physical Geography 287 

Meteorology " 311 

Atmospheric Pressure 315 

Climatology 317 

The Snow-line 329 

Hygrometry 332 

Atmospheric Electricity 335 

Organic Life 339 

Motion in Plants 341 

Universality of Animal Life 342 

Geography of Plants and Animals 346 

Floras of different Countries 350 

Man 352 

Races 353 

Language 357 

Conclusion of the Subject < 359 



SUMMARY. 

Translator's Preface. 
Author's Preface. 

« 

Vol. I. 

GENERAL SUMMARY OF THE CONTENTS. 

Introduction. — Rejlections on the different Degrees of Enjoyment pre' 
sented to us by the Aspect of Nature and the scientific Exposition of 
the Laws of the Universe Page 23-78 

Insight mto the connection of phenomena as the aim of all natural 
investigation. Nature presents itself to meditative contemplation as a 
jnity in diversity. Differences in the grades of enjoyment yielded by 
nature. Effect of contact with free nature ; enjoyment derived from 
nature independently of a knowledge of the action of natural forces, or 
of the effect produced by the individual character of a locality. Effect 
of the physiognomy and configuration of the surface, or of the character 
of vegetation. Reminiscences of the woody valleys of the Cordilleras 
and of the Peak of Teneriffe. Advantages of the mountainous region 
near the equator, where the multiplicity of natural impressions attains 
its maximum within the most circumscribed limits, and where it is 
permitted to man simultaneously to behold all the stars of the firma- 
ment and all the forms of vegetation — p. 23-33. 

Tendency toward the investigation of the causes of physical phenom 
ena. Erroneous views of the character of natural forces arising from 
an imperfect mode of observation or of induction. The crude accu- 
mulation of physical dogmas transmitted from one century to another. 
Their diffusion among the higher classes. Scientific physics are asso- 
ciated with another and a deep-rooted system of untried and misunder- 
stood experimental positions. Investigation of natural laws. Appre- 
hension that nature may lose a portion of its secret charm by an inquiry 
into the internal character of its forces, and that the enjoyment of na 
ture must necessarily be weakened by a study of its domain. Advant 
ages of general views which impart an exalted and solemn character 
to natural science. The possibility of separating generalities from 
specialities. Examples drawn from astronomy, recent optical discov 
eries, physical geognosy, and the geography of plants. Practicabil 
ity of the study of physical cosmography — p. 33-54. Misunderstood 
popular knowledge, confounding cosmography with a mere encyclope- 
dic enumeration of natural sciences. Necessity for a simultaneous re- 
gard for all branches of natural science. Influence of this study on 
national prosperity and the welfare of nations ; its more earnest and 
characteristic aim is an inner one, arising from exalted mental activity. 
Mode of treatment with regard to the object and presentation ; recip- 
rocal connection existing between thought and speech — p. 54-5C 

The notes to p. 28-33. Comparative hypsometrical data of the eleva- 
tions of the Dhawalagiri, Jawahir, Chimborazo, iEtna (according to the 
measureraeutof Sir John Herschel), the Swiss Alps, &c. — p. 28. Rarity 



XVI SUMMARY OF THE CONTENTS. 

of palms and ferns in the Himalaya Mountains — p. 29. European vz- 
etable forms in the Indian Mountains — p. 30. Northern and southern 
limits of perpetual snow on the Himalaya ; influence of the elevated 
plateau of Thibet — p. 30-33. Fishes of an earlier world — p. 46. 

Limits and Method of Exposition of the ^Physical Description of the 

Universe Page 56-78 

Subjects embraced by the study of the Cosmos or of physical cosmog 
raphy. Separation of other kindred studies — p. 56-62. The urano- 
logical portion of the Cosmos is more simple than the telluric ; the im- 
possibility of ascertaining the diversity of matter simplifies the study 
of the mechanism of the heavens. Origin of the word Cosmos, its sig- 
nification of adornment and order of the universe. The existijig can 
not be absolutely separated in our contemplation of nature from the 
future. Histoiy of the world and description of the world — p. 62-73. 
Attempts to embrace the multiplicity of the phenomena of the Cos- 
mos in the unity of thought and under the form of a purely rational 
combination. Natural philosophy, which preceded all exact observa- 
tion in antiquity, is a natural, but not unfrequently ill-directed, eftbrt 
of reason. Two forms of abstraction rule the whole mass of knowl- 
edge, viz.: the quantitative, relative deteraiinations according to num- 
ber and magnitude, and qualitative, material characters. Means of 
submitting phenomena to calculation. Atoms, mechanical methods of 
construction. Figurative representatiojus ; mythical conception of im- 
ponderable matters, and the peculiar vital forces in every organism. 
That which is attained by obsex-vation and experiment (calling forth 
phenomena) leads, by analogy and induction, to a knowledge of empir- 
ical laws; their gradual simplification and generalization. Arrange- 
ment of the facts discovered in accordance with leading ideas. The 
treasure of empirical contemplation, collected through ages, is in no dan- 
ger of experiencing any hostile agency from philosophy — p. 73-78. 

[In the notes appended to p. 66-70 are considerations of the general 
and comparative geography of Varenius. Philological investigation 
into the meaning of the words Koafiog and mundus.'] 

Delineation of Nature. General Review of Natural Phenomena 

p. 79-359 

Introduction — p. 79-83. A descriptive delineation of the world 
embraces the whole universe {to tt&v) in the celestial and terrestrial 
spheres. Form and course of the representation. It begins with the 
depths of space, of which we know little beyond the existence of 
laws of gravitation, and with the region of the remotest nebulous spots 
and double stars, and then, gradually descending through the starry 
stratum to w^hich our solar system belongs, it contemplates this terres- 
trial spheroid, surrounded by air and water, and, finally, proceeds to 
the consideration of the form of our planet, its temperature and mag- 
netic tension, and the fullness of organic vitality which is unfolded on 
its surface under the action of light. Partial insight into the relative 
dependence existing among all phenomena. Amid all the mobile and 
unstable elements in space, mean numerical vahces are the ultimate aim 
of investigation, being the expression of the physical laws, or forces of 
the Cosmos. The delineation of the universe does not begin with the 
eai'th, from which a merely subjective point of view might have led ua 
to start, but rather with the objects comprised in the regions of space. 
Distribution of matter, which is partially conglomerated into rotating 



SUMMARY OF THE CONTENTS. XVil 

nnd circling heavenly bodies of veiy different density and magnitude, 
and partly scattered as self-luminous vapor. Review of the separate 
portions of the picture of nature, for the purpose of explaining the re- 
ciprocal connection of all phenomena. 

I. Celestial Portion of the Cosmos Page 83-154 

II. Terrestrial Portion, of the Cosmos p. 154-359 

a. Form of the earth, its mean density, quantity of heat, electro-mag- 
netic activity, process of light — p. 154-202. 

b. Vital activity of the earth toward its external surface. Reaction 
of the interior of a planet on its crust and surface. Subterranean noise 
without waves of concussion. Earthquakes dynamic phenomena — 
p. 202-217. 

c. Mateiial pi'oducts which frequently accompany earthquakes. Gas- 
eous and aqueous springs. Salses and mud volcanoes Upheavals of 
the soil by elastic forces — p. 217-228. 

d. Fire-emitting mountains. Craters of elevation. Distribution of 
volcanoes on the earth — p. 228-247. 

e. Volcanic foi'ces form new kinds of rock, and metamorphose those 
already existing. Geognostical classification of rocks into four groups. 
Phenomena of contact. Fossiliferous strata ; their vertical arrangement. 
The faunas and floras of an earlier world. Distribution of masses of 
rock— p. 247-284. 

/. Geognostical epochs, which are indicated by the mineralogical dif- 
ference of rocks, have determined the distnbution of solids and fluids 
into continents and seas. Individual configuration of solids into hori- 
zontal expansion and vertical elevation. Relations of area. Articula- 
tion. Probability of the continued elevation of the earth's crust in 
ridges— p. 284-301. 

0-. Liquid and aenform envelopes of the solid surface of our planet. 
Distribution of heat in both. The sea. The tides. CuiTents and their 
effects— p. 301-311. 

h. The atmosphere. Its chemical composition. Fluctuations in its 
density. Law of the direction of the winds. Mean temperature. Enu- 
meration of the causes which tend to raise and lower the temperature. 
Continental and insular climates. East and west coasts. Cause of the 
curvature of the isothermal lines. Limits of perpetual snow. Quantity 
of vapor. Electricity in the atmosphere. Forms of the clouds — p. 
311-339. 

i. Separation of inorganic terrestrial life from the geogi-aphy of vital 
organisms; the geography of vegetables and animals. Physical grada- 
tions of the human race — p. 339-359. 

Special Analysis of the Delineation of Nature, including References to the 

Subjects treated of in the Notes. 

[. Celestial Portion of the Cosmos p. 83-154 

The universe and all that it compnses — multiform nebulous spots, 
planetary vapor, and nebulous stai-s. The pictui'esque charm of a 
southern sky — note, p. 85. Conjectures on the position in space of 
the world. Our stellar masses. A cosmical island. Gauging stars. 
Double stars revolving round a common center. Distance of the star 6 1 
Cygui — p. 88 and note. Our solar system more complicated than was 
conjectured at the close of the last century. Primary planets with Nep- 
tune, Astrea, Hebe, Iris, and Flora, now constitute 16 ; secondary plan- 
ets 18 ; myriads of comets of which many of the inner ones are inclosed 



XVm SUMMARY OF THE CONTENTS. 

in the orbits of the planets ; a rotating ring (the zodiacal light) and me- 
teoric stones, probably to be regarded as small cosmical bodies. The 
telescopic planets, Vesta, Junoj Ceres, Pallas, Astrea, Hebe, Iris, and 
Flora, with their frequently intersecting, strongly inclined, and more 
eccentric orbits, constitute a central group of separation between the 
inner planetary group (Mercury, Venus, the Earth, and Mars) and the 
outer group (Jupiter, Saturn, Uranus, and Neptune). Contrasts of these 
planetary groups. Relations of distance from one central body. Dif- 
fei'ences of absolute magnitude, density, period of revolution, eccentric- 
ity, and inclination of the orbits. The so-called law of the distances of 
the planets from their central sun. The planets which have the largest 
number of moons — p. 96 and note. Relations in space, both absolute 
and relative, of the secondary planets. Largest and smallest of the 
moons. Greatest appi'oximation to a primary planet. Retrogressive 
movement of the moons of Uranus. Libration of the Earth's satellite — 
p. 98 and note. Comets ; the nucleus and tail ; various forms and di- 
rections of the emanations in conoidal envelopes, with more or less 
dense walls. Several tails inclined toward the sun ; change of form of 
the tail; its conjectured rotation. Nature of light. Occultations of the 
fixed stars by the nuclei of comets. Eccentricity of their orbits and 
periods of revolution. Greatest distance and greatest approximation 
of comets. Passage through the system of Jupiter's satellites. Comets 
of short periods of revolution, more correctly termed inner comets 
(Encke, Biela, Faye) — p. 107 and note. Revolving a6rolites (meteoric 
stones, fire-balls, falling stars). Their planetary velocity, magnitude, 
form, observed height. Periodic return in streams; the November 
stream and the stream of St. Lawrence. Chemical composition of me- 
teoric asteroids — p. 130 and notes. Ring of zodiacal light. Limita- 
tion of the present solar atmosphere — p. 141 and note. Translatory 
motion of the whole solar system — p. 145-149 and note. The exist- 
ence of the law of gravitation beyond our solar system. The milky 
way of stars and its conjectured breaking up. Milky way of nebulous 
spots, at right angles with that of the stars. Periods of revolutions of 
bi-colored double stars. Canopy of stars; openings in the stellar stra- 
tum. Events in the universe ; the apparition of new stars. Propaga- 
tion of light, the aspect of the stai'ry vault of the heavens conveys to the 
mind an idea of inequality of time — p. 149-154 and notes. 

II. Terrestrial Portion of the Cosmos Page 154-359 

a. Figure of the earth. Density, quantity of heat, electro-magnetic 
tension, and terrestrial light — p. 154-202 and note. Knowledge of 
the compression and curvature of the earth's surface acquired by meas- 
urements of degrees, pendulum oscillations, and certain inequalities in 
the moon's orbit. Mean density of the earth. The earth's crust, and 
the depth to which we are able to penetrate — p. 159, 160, note. Three- 
fold movement of the heat of the earth ; its thermic condition. Law 
of the increase of heat with the increase of depth — p. 160, 161 and note. 
Magnetism electricity in motion. Periodical variation of terrestrial 
magnetism. Disturbance of the regular course of the magnetic needle. 
Magnetic stoiins ; extension of their action. Manifestations of magnet- 
ic force on the earth's surface presented under three classes of phe- 
nomena, namely, lines of equal force (isodynamic), equal inclination 
(isoclinic), and equal deviation (isogenic). Position of the magnetic 
pole. Its probable connection with the poles of cold. Change of all 
the magnetic phenomena of the earth. Erection of magnetic observa- 



SUMMARY OF THE CONTENTS. XIX 

toi-ies since 1828 ; a far-extending net-work of magnetic stations — p. 
190 and note. Development of light at the magnetic poles; terrestrial 
light as a consequence of the electro-magnetic activity of our planet. 
Elevation of polar light. Whether magnetic storms are accompanied 
by noise. Connection of polar light (an electro-magnetic development 
of light) with the formation of cirrus clouds. Other examples of the 
generation of terrestrial light — p. 202 and note. 

b. The vital activity of a planet manifested from within outward, the 
principal source of geognostic phenomena. Connection between mere- 
ly dynamic concussions or the upheaval of whole portions of the earth's 
crust, accompanied by the eflfusion of matter, and the generation of 
gaseous and liquid fluids, of hot mud and fused earths, which solidify 
into rocks. Volcanic action, in the most general conception of the idea, 
is the reaction of the interior of a planet on its outer surface. Earth- 
quakes. Extent of the circles of commotion and their gradual increase. 
Whether there exists any connection between the changes in terres- 
trial magnetism and the processes of the atmosphere. Noises, subter- 
ranean thunder without any perceptible concussion. The rocks which 
modify the propagation of the waves of concussion. Upheavals ; erup- 
tion of water, hot steam, mud mofettes, smoke, and flame during au 
earthquake — p. 202-218 and notes. 

c. Closer consideration of material products as a consequence of 
internal planetary activity. There rise from the depths of the earth, 
through fissures and cones of eruption, various gases, liquid fluids (pure 
or acidulated), mud, and molten earths. Volcanoes are a species of 
intermittent spring. Temperature of thermal springs; their constancy 
and change. Depth of the foci — p. 219-224 and notes. Salses, mud 
volcanoes. While fire-emitting mountains, being sources of molten 
earths, produce volcanic rocks, spring water forms, by precipitation, 
strata of limestone. Continued generation of sedimentary rocks — p 
228 and note. 

d. Diversity of volcanic elevations. Dome-like closed trachytic 
mountains. Actual volcanoes which are formed from craters of eleva- 
tion or among the detritus of their original structure. Permanent con- 
nection of the interior of our earth with the atmosphere. Relation to 
certain rocks. Influence of the relations of height on the frequency of 
the eruptions. Height of the cone of cinders. Characteristics of those 
volcanoes v^'hich rise above the snow-line. Columns of ashes and fire. 
Volcanic storm during the eruption. Mineral composition of lavas — 
p. 236 and notes. Distribution of volcanoes on the earth's surface ; 
central and linear volcanoes ; insular and littoral volcanoes. Distance 
of volcanoes from the sea-coast. Extinction of volcanic forces — p. 246 
and notes. 

e. Relation of volcanoes to the character of rocks. Volcanic forces 
form new rocks, and metamorphose the more ancient ones. The study 
of these relations leads, by a double course, to the mineral portion of 
geognosy (the study of the textures and of the position of the earth's 
strata), and to the configuration of continents and insular groups ele- 
vated above the level of the sea (the study of the geographical form 
and outlines of the different pai*ts of the earth). Classification of rocks 
according to the scale of the phenomena of structure and metamorpho- 
sis, which are still passing before our eyes. Rocks of eruption, sedi- 
mentary rocks, changed (metamorphosed) rocks, conglomerates — com- 
pound rocks are definite associations of oryctognostically simple fossils 
There are four phases in the formative condition: rocks of eruption. 



XX SUMIMARY OF THE CONTENTS. 

endogenous (granite, sienite, porphyry, greenstone, hypersthene, rockj 
eupliotide, melapbyre, basalt, and phonolithe); sedimentary rocks (si- 
lurian schist, coal measures, limestone, travertino, infusorial deposit) ; 
metamorphosed rock, which contains also, together with the detritus 
of the rocks of eruption and sedimentary rocks, the remains of gneiss, 
mica schist, and more ancient metamorphic masses. Aggregate and 
sandstone formations. The phenomenon of contact explained by the 
artificial imitation of minerals. Effects of pressure and the various ra- 
pidity of cooling. Origin of granular or saccharoidal marble, silicifica- 
tion of schist into ribbon jasper. Metamorphosis of calcareous marl 
into micaceous schist through granite. Conversion of dolomite and 
granite into argillaceous schist, by contact with basaltic and doleritie 
rocks. Filling up of the veins from below. Processes of cementation 
in agglomerate structures. Friction conglomerates — p. 269 and note. 
Relative age of rocks, chronometry of the earth's crust. Fossiliferous 
strata. Relative age of organisms. Simplicity of the first \atal forms. 
Dependence of physiological gradations on the age of the formations. 
Geognostic horizon, whose careful investigation may yield certain data 
regarding the identity or the relative age of formations, the periodic 
recurrence of certain strata, their parallelism, or their total suppression. 
Types of the sedimentary structures considered in their most simple 
and general characters ; silurian and devonian formations (formerly 
known as rocks of transition); the lower trias (mountain limestone, 
coal measures, together with todtliegende and zechstein) ; the upper 
ti'ias (bunter sandstone, muschelkalk, and keuper) ; Jura limestone (lias 
and oolite) ; freestone, lower and upper chalk, as the last of the flotz 
strata, which begin with mountain limestone ; tertiaiy formations in 
three divisions, which are designated by granular limestone, lignite, 
and south Apennine gravel — p. 269-278. 

The faunas and floras of an earlier world, and their relations to exist- 
ing organisms. Colossal bones of antediluvian mammalia in the upper 
alluvium. Vegetation of an earlier world ; monuments of the history 
of its vegetation. The points at which certain vegetable groups attain 
their maximum; cycadeae in the keuper and lias, and coniferae in the 
bunter sandstone. Lignite and coal measures (amber-tree). Deposition 
of large masses of rock ; doubts regarding their origin — p. 285 and note 

/. The knowledge of geognostic epochs — of the upheaval of mount- 
ain chains and elevated plateaux, by which lands are both formed and 
destroyed, leads, by an internal causal connection, to the distribution 
into solids and fluids, and to the peculiarities in the natural configura- 
tion of the earth's surface. Existing areal relations of the solid to the 
fluid differ considerably from those presented by the maps of the phys- 
ical portion of a more ancient geography. Importance of the eruption 
of quartzose porphyry with reference to the then existing configuration 
of continental masses. Individual conformation in horizontal exten- 
sion (relations of articulation) and in vertical elevation (hypsometrical 
views). Influence of the relations of the area of land and sea on the 
temperature, direction of the winds, abundance or scarcity of organic 
products, and on all meteorological processes collectively. Direction 
of the major axes of continental masses. Articulation and pyramidal 
termination toward the south. Series of peninsulas. Valley-like form- 
ation of the Atlantic Ocean. Forms which frequently recur — p. 285- 
293 and notes. Ramifications and systems of mountain chains, and tho 
means of determining their relative ages. Attempts to determine the 
*enter of gravity of the volume of the lauds upheaved above the level 



SUMMARY OF THE CONTENTS. XXI 

of the sea. The elevation of continents is still progressing slowly, and 
is being compensated for at some definite points by a perceptible sink- 
ing. All geognostic phenomena indicate a periodical alternation of 
activity in the interior of our planet. Probability of new^ elevations of 
ridges — p. 293-301 and notes. 

g. The solid surface of the earth has two envelopes, one liquid, and 
tlie other aeriform. Contrasts and analogies which these envelopes— 
tlie sea and the atmosphere — present in their conditions of aggrega^ 
tion and electricity, and in their relations of currents and temperature. 
Depths of the ocean and of the atmosphei-e, the shoals of which consti 
tute our highlands and mountain chains. The degree of heat at the 
surface of the sea in different latitudes and in the lower strata. Tend- 
ency of the sea to maintain the temperature of the surface in the strata 
nearest to the atmosphere, in consequence of the mobility of its j)arti- 
cles and the alteration in its density. Maximum of the density of salt 
water. Position of the zones of the hottest water, and of those having 
the greatest saline contents. Thermic influence of the lower polar cur- 
rent and the counter currents in the straits of the sea — p. 302-304 and 
notes. General level of the sea, and permanent local disturbances of 
equilibrium ; the periodic disturbances manifested as tides. Oceanic 
currents; the equatorial or rotation current, the Atlantic warm Gulf 
Stream, and the further impulse which it receives; the cold Peruvian 
stream in the eastern portion of the Pacific Ocean of the southern zone. 
Temperature of shoals. The universal diffusion of life in the ocean. 
Influence of the small submarine sylvan region at the bottom of beds 
of rooted algse, or on far-extending floating layers of fucus — p. 302-311 
and notes. 

k. The gaseous envelope of our planet, the atmosphere. Chemical 
composition of the atmosphere, its transparency, its polarization, pres 
sure, temperature, humidity, and electric tension. Relation of oxygen 
to nitrogen ; amount of carbonic acid; carbureted hydrogen; ammo- 
niacal vapors. Miasmata. Regular (horaiy) changes in the pressure 
of the atmosphere. Mean barometrical height at the level of the sea 
in different zones of the earth. Isobarometx'ical curves. Barometrical 
windroses. Law of rotation of the winds, and its importance with ref- 
erence to the knowledge of many meteorological processes. Land and 
sea winds, trade winds and monsoons — p. 311-317. Climatic distribu- 
tion of heat in the atmosphere, as the effect of the relative position of 
transparent and opaque masses (fluid and solid superficial area), and 
of the hypsometrical configuration of continents. Curvature of the iso- 
thermal lines in a horizontal and vertical direction, on the earth's sur- 
face and in the superimposed strata of air. Convexity and concavity 
of the isothermal lines. Mean heat of the year, seasons, months, and 
days. Enumeration of the causes which produce disturbances in the 
form of the isothermal lines, i. e., their deviation from the position of the 
geographical parallels. Isochimenal and isotheral lines are the lines of 
equal winter and summer heat. Causes which raise or lower the tem- 
perature. Radiation of the earth's surface, according to its inclination, 
color, density, dryness, and chemical composition. The form of the 
cloud which announces what is passing in the upper strata of the atmos- 
phere is the image of the strongly radiating ground projected on a hot 
summer sky. Contrast between an insular or littoral climate, such as 
is experienced by all deeply-articulated continents, and the climate of 
the interior of large tracts of land. East and west coasts. Ditlerence 
between the southern and northern hemispheres. Thennal scales of 



XXll SUMMARY OF THE CONTENTS. 

cultivated plants, going down from the vanilla, cacoa, and musacese, to 
citrons and olives, and to vines yielding potable wines. The influence 
which these scales exercise on the geographical distribution of culti- 
vated plants. The favorable ripening and the immaturity of fruits are 
essentially influenced by the difference in the action of direct or scat- 
tered light in a clear sky or in one overcast with mist. General sum- 
mary of the causes which yield a more genial climate to the greater 
portion of Europe considered as the western peninsula of Asia — ^p. 326. 
Determination of the changes in the mean annual and summer temper- 
ature, which correspond to one degree of geographical latitude. Equal- 
ity of the mean temperature of a mountain station, and of the polar dis- 
tance of any point lying at the level of the sea. Decrease of tempera- 
ture with the decrease in elevation. Limits of perpetual snow, and the 
fluctuations in these limits. Causes of disturbance in the regularity of 
the phenomenon. Northern and southern chains of the Himalaya; hab- 
itability of the elevated plateaux of Thibet — p. 33 1 . Quantity of moist- 
ure in the atmosphere, according to the hours of the day, the seasons of 
the year, degrees of latitude, and elevation. Greatest dryness of the 
atmosphere observed in Northern Asia, between the river disti-icts of 
the Irtysch and the Obi. Dew, a consequence of radiation. Quantity 
of rain — p. 335. Electricity of the atmosphere, and disturbance of the 
electric tension. Geographical distribution of storms. Predetermina 
tion of atmospheric changes. The most important climatic disturbances 
can not be traced, at the place of observation, to any local cause, but are 
rather the consequence of some occurrence by which the equilibrium 
in the atmospheric currents has been destroyed at some considerable 
distance — p. 335-339. 

i. Physical geography is not limited to elementary inorganic terres- 
trial life, but, elevated to a higher point of view, it embraces the sphere 
of organic life, and the numerous gradations of its typical development. 
Animal and vegetable life. General diffusion of life in the sea and on 
the land; microscopic vital forms discovered in the polar ice no less 
than in the depths of the ocean within the tropics. Extension imparted 
to the horizon of life by Ehrenberg's discoveries. Estimation of the 
mass (volume) of animal and vegetable organisms — p. 339-346. Geog- 
raphy of plants and animals. Migrations of organisms in the ovum, or 
by means of organs capable of spontaneous motion. Spheres of distri- 
bution depending on climatic relations. Regions of vegetation, and 
classification of the genera of animals. Isolated and social living plants 
and animals. The character of floras and faunas is not deteimined so 
much by the predominance of separate families, in certain parallels of 
latitude, as by the highly complicated relations of the association of many 
families, and the relative numerical value of their species. The forms 
of natural families which increase or decrease from the equator to the 
poles. Investigations into the numerical relation existing in different 
districts of the earth between each one of the large families to the 
whole mass of phanerogamia — p. 346-351. The human race considered 
according to its physical gradations, and the geographical distribution 
of its simultaneously occurring types. Races and varieties. All races 
of men are forms of one single species. Unity of the human race. 
Languages considered as the intellectual creations of mankind, or as 
portions of the history of mental activity, manifest a character of nation- 
ality, although certain historical occurrences have been the means of 
diffusing idioms of the same family of languages among nations of wholb^ 
different descent — p. 351-359. 



INTRODUCTION. 



REFLECTIONS ON THE DIFFERENT DEGREES OF ENJOYMENT PRE- 
SENTED TO US BY THE ASPECT OF NATURE AND THE STUDY OF HER 
LAWS. 

In attempting, after a long absence from my native coun- 
try, to develop the physical phenomena of the globe, and the 
simultaneous action of the forces that pervade the regions of 
space, I experience a two-fold cause of anxiety. The subject 
before me is so inexhaustible and so varied, that I fear either 
to fall into the superficiality of the encyclopedist, or to weary 
the mind of my reader by aphorisms consisting of mere gener- 
alities clothed in dry and dogmatical forms. Undue concise- 
ness often checks the flow of expression, while diffuseness is 
alike detrimental to a clear and precise exposition of our ideas. 
Nature is a free domain, and the profound conceptions and 
enjoyments she awakens within us can only be vividly deline- 
ated by thought clothed in exalted forms of speech, worthy of 
bearing witness to the majesty and greatness of the creation. 

In considering the study of physical phenomena, not mere- 
ly in its bearings on the material wants of life, but in its gen- 
eral influence on the mtellectual advancement of rnankmd, 
we find its noblest and most important result to be a knowl- 
edge of the chain of connection, by which all natural forces 
are linked together, and made mutually dependent upon each 
other ; and it is the perception of these relations that exalts 
our views and ennobles our enjoyments. Such a result can, 
however, only be reaped as the fruit of observation and intel- 
lect, combined wdth the spirit of the age, in which are reflect- 
ed all the varied phases of thought. He who can trace, 
through by-gone times, the stream of our knowledge to its 
primitive source, will learn from history how, for thousands 
of years, man has labored, amid the ever-recurring changes 
of form, to recognize the invariability of natural laws, and 
has thus, by the force of mind, gradually subdued a great por- 
tion of the physical world to his dominion. In interrogating 
the history of the past, we trace the mysterious course of ideas 
yielding the first glimmering perception of the same imag'i of 



24 COSMOS. 

a Cosmos, or harmoniously ordered whole, which, dimly shad- 
owed forth to the human mind in the primitive ages of the 
world, is now fully revealed to the maturer intellect of man 
kind as the result of long and laborious observation. 

Each of these epochs of the contemplation of the external 
Vorld — the earliest dawn of thought and the advanced stage 
of civilization — has its oWii source of enjoyment. In the 
former, this enjoyment, in accordance with the simplicity of 
the primitive ages, flowed from an intuitive feeling of the or 
der that was proclaimed by the invariable and successive re- 
appearance of the heavenly bodies, and by the progressive de- 
velopment of organized beings ; while in the latter, this sense 
of enjoyment springs from a definite knowledge of the phe- 
nomena of nature. When man began to interrogate nature, 
and, not conteijt with observing, learned to evoke phenomena 
under definite conditions ; when once he sought to collect and 
record facts, in order that the fruit of liis labors might aid in- 
vestigation after his own brief existence had passed aw^ay, the 
philosophy of Nature cast aside the vague and poetic garb 
in which she had been enveloped from her origin, and, having 
assumed a severer aspect, she now w^eighs the value of ob- 
servations, and substitutes induction and reasoning for con- 
jecture and assumption. The dogmas of former ages survive 
now only in the superstitions of the people and the prejudices 
of the ignorant, or are perpetuated in a few systems, which, 
conscious of their weakness, shroud themselves in a vail of 
mystery. We may also trace the same primitive intuitions 
in lanffuaofes exuberant in fisfurative exDressions ; and a few 
of the best chosen symbols engendered by the happy inspira- 
tion of the earliest ages, having by degrees lost their vague- 
ness through a better mode of interpretation, are still preserved 
among our scientific terms. 

Nature considered rationally, that is to say, submitted to 
the process of thought, is a unity in diversity of phenomena ; 
a harmony, blending together all created things, however dis- 
similar in form and attributes ; one great whole {to -rrdv) an- 
imated by the breath of life. The most important result of 
a rational inquiry into nature is, therefore, to establish the 
unity and harmony of this stupendous mass of force and mat- 
ter, to determine with impartial justice what is due to the 
discoveries of the past and to those of the present, and to an- 
alyze the individual parts of natural phenomena without suo- 
cumbing beneath the weight of the whole. Thus, and thus 
alone, is it permitted to man, while mindful of the high des- 



INTRODUCTION. 25 

tiny of his race, to comprehend nature, to lift the vail that 
shrouds her phenomena, and, as it were, submit the results of 
observation to the test of reason and of intellect. 

In reflecting upon the different degrees of enjoyment pre- 
sented to us in the contemplation of nature, we find that the 
ftrst place must be assigned to a sensation, which is wholly 
mdependent of an intimate acquaintance with the physical 
phenomena presented to our view, or of the peculiar character 
of the region surrounding us. In the uniform plain bounded 
only by a distant horizon, where the lowly heather, the cistus, 
or waving grasses, deck the soil ; on the ocean shore, where 
the waves, softly rippling over the beach, leave a track, green 
with the weeds of the sea ; every where, the mind is penetra- 
ted by the same sense of the grandeur and vast expanse of 
nature, revealing to the soul, by a mysterious inspiration, the 
existence of laws that regulate the forces of the universe. 
Mere communion with nature, mere contact with the free air, 
exercise a soothing yet strengthening influence on the wearied 
spirit, calm the storm of passion, and soften the heart when 
shaken by sorrow to its inmost depths. Every where, in ev 
ery region of the globe, in every stage of intellectual culture, 
the same sources of enjoyment are alike vouchsafed to man. 
The earnest and solemn thoughts awakened by a communion 
with nature intuitively arise from a presentiment of the order 
and harmony pervading the whole universe, and from the 
contrast we draw between the narrow limits of our own ex- 
istence and the image of infinity revealed on every side, wheth- 
er we look upward to the starry vault of heaven, scan the far- 
stretching plain before us, or seek to trace the dim horizon 
across the vast expanse of ocean. 

The contemplation of the individual characteristics of the 
landscape, and of the conformation of the land in any definite 
region of the earth, gives rise to a different source of enjoy- 
ment, awakening impressions that are more vivid, better de- 
fined, and more congenial to certain phases of the mind, than 
those of which we have already spoken. At one time the 
hiiart is stirred by a sense of the grandeur of the face of na- 
ture, by the strife of the elements, or, as in Northern Asia, by 
the aspect of the dreary barrenness of the far-stretching steppes ; 
at another time, softer emotions are excited by the contempla- 
tion of rich harvests wrested by the hand of man from the 
wild fertility of nature, or by the sight of human habitations 
raised beside some wild and foaming torrent. Here I regard 
less the degree of intensity than the difference existing in the 

Vol. I.— B 



26 COSMOS. 

various sensations that derive their charm and peimauencf 
from the pecuhar character of the scene. 

If I might be allowed to abandon myself to the recollections 
»f my own distant travels, I would instance, among the most 
•■■triking scenes of nature, the calm sublimity of a tropical night, 
ivhen the stars, not sparkling, as in our northern skies, shed 
cheir soft and planetary light over the gently-heaving ocean ; 
)r I would recall the deep valleys of the Cordilleras, where 
",he tall and slender palms pierce the leafy vail around them, 
ind waving on high their feathery and arrow-like branches, 
';brm, as it were, " a forest above a forest ;"* or I would de- 
scribe the summit of the Peak of TenerifTe, when a horizontal 
.ayer of clouds, dazzling in whiteness, has separated the cone 
)f cinders from the plain below, and suddenly the ascending 
iurrent pierces the cloudy vail, so that the eye of the traveler 
may range from the brink of the crater, along the vine-clad 
slopes of Orotava, to the orange gardens and banana groves 
that skirt the shore. In scenes like these, it is not the peace- 
ful charm uniformly spread over the face of nature that moves 
the heart, but rather the peculiar physiognomy and conforma- 
tion of the land, the features of the landscape, the ever-vary- 
ing outline of the clouds, and their blending with the horizon 
of the sea, whether it lies spread before us like a smooth and 
shining mirror, or is dimly seen through the morning mist. 
All that the senses can but imperfectly comprehend, all that 
is most awful in such romantic scenes of nature, may become 
1 source of enjoyment to man, by opening a wide field to the 
creative powers of his imagination. Impressions change with 
the varying movements of the mind, and we are led by a hap- 
py illusion to believe that we receive from the external world 
that with which we have ourselves invested it. 

When far from our native country, after a long voyage, we 
;read for the first time the soil of a tropical land, v/e expe- 
•ience a certain feeling of surprise and gratification in recog- 
lizing, in the rocks that surround us, the same inclined schis- 
I ose strata, and the same columnar basalt covered with cellu- 
iar amygdaloids, that we had left in Europe, and whose iden- 
iity of character, in. latitudes so widely different, reminds us 
!.hat the solidification of the earth's crust is altogether inde- 
[leudent of climatic influences. But these rocky masses of 
schist and of basalt are covered with vogetation of a character 
with wluch we are unacquainted, and of a physiognomy wholly 

* This expression is taken from a beautiful description of tropical 
forest sceiieiy iu Paul and Virginia, by Bernardin de Saint Pierre. 



INTRODUCTION. 27 

unknown to us ; and it is then, amid the colossal and majestic 
forms of an exotic flora, that we feel how wonderfully the flex- 
ibility of our nature fits us to receive new impressions, linked 
together by a certain secret analogy. We so readily perceive 
the affinity existing among all the forms of organic life, thai 
although the sight of a vegetation similar to that of our native 
country might at first be most welcome to the eye, as the sweel 
familiar sounds of our mother tongue are to the ear, we nev- 
ertheless, by degrees, and almost imperceptibly, become famil 
iarized with a new home and a new climate. As a true citi 
zen of the world, man eveiy where habituates himself to tha' 
which surrounds him ; yet fearful, as it were, of breaking tl ^ 
links of association that bind him to the home of his childhood, 
the colonist applies to some few plants in a far-distant clime the 
names he had been familiar Avith in his native land ; and by 
the mysterious relations existing among all types of organiza- 
tion, the forms of exotic vegetation present themselves to his 
mind as nobler and more perfect developments of those he had 
loved in earher days. Thus do the spontaneous impressions 
of the untutored mind lead, like the laborious deductions of 
cultivated intellect, to the same intimate persuasion, that one 
sole and indissoluble chain binds together all nature. 

It may seem a rash attempt to endeavor to separate, into 
its different elements, the magic power exercised upon our 
minds by. the physical world, since the character of the land- 
scape, and of every imposing scene in nature, depends so ma- 
terially upon the mutual relation of the ideas and sentiments 
simultaneously excited in the mind of the observer. 

The powerful effect exercised by nature springs, as it were, 
from the connection and unity of the impressions and emo- 
tions produced ; and we can only trace their different sources 
by analyzing the individuality of objects and the diversity of 
forces. 

The richest and most varied elements for pursuing an anal- 
ysis of this nature present themselves to the eyes of the trav- 
eler in the scenery of Southern Asia, in the Great Indian 
Archipelago, and more especially, too, in the New Continent, 
where the summits of the lofty Cordilleras penetrate the con- 
fines of the aerial ocean surrounding our globe, and where the 
same subterranean forces that once raised these mountain 
chains still shake them to their foundation and threaten their 
downfall. 

Graphic delineations of nature, arranged according to sys- 
teraatic views, are not only suited to please the imagination, 



28 COSMOS. 

but may also, when properly considered, indicate the grades 
of the impressions of which I have spoken, from the miiform- 
ity of the sea-shore, or the barren steppes of Siberia, to the 
inexhaustible fertility of the torrid zone. If we were even to 
picture to ourselves Mount Pilatus placed on the Schreck- 
horn,* or the Schneekoppe of Silesia on Mont Blanc, we should 

* These comparisons are only approximative. The several eleva- 
tions above the level of the sea are, in accurate numbers, as follows : 

The Schneekoppe or Riesenkoppe, in Silesia, about 5270 feet, ac- 
cording to Hallaschka. The Righi, 5902 feet, taking the height of the 
Lake of Lucerne at 1426 feet, according to Eschman. (See Compte 
Rendu des Mesures Ti-igonometriques en Suisse, 1840, p. 230.) Mount 
Athos, 6775 feet, according to Captain Gaultier; Mount Pilatus, 7546 
feet; Mount ^Etna, 10,871 feet, according to Captain Smyth; or 10,874 
feet, according to the barometrical measurement made by Sir John 
Herschel, and communicated to me in writing in 1825, and 10,899 feet, 
according to angles of altitude taken by Cacciatore at Palermo (calcu- 
lated by assuming the terrestrial refraction to be 0'076) ; the Schreck 
horn, 12,383 feet; the Jungfrau, 13,720 feet, according to TraUes ; Mont 
Blanc, 15,775 feet, according to the diflferent measurements considered 
by Roger {Bibl. Univ., May, 1828, p. 24-53), 15,733 feet, according to 
the measurements taken from Mount Columbier by Carlini in 1821, and 
15,748 feet, as measured by the Austrian engineers from Trelod and 
the Glacier d'Ambin. 

The actual height of the Swiss mountains fluctuates, according to 
Eschman's observations, as much as 25 English feet, owing to the vary- 
ing thickness of the stratum of snow that covers the summits. Chim- 
borazo is, according to my trigonometrical measurements, 21,421 feet 
(see Humboldt, Recueil d^Obs. Astr., tome i., p. 73), and Dhawalagiri, 
28,074 feet. As there is a dilference of 445 feet between the determin- 
ations of Blake and Webb, the elevation assigned to the Dhawalagiri 
(or white mountain, from the Sanscrit dhawala, white, and giri, mount- 
ain) can not be received with the same confidence as that of the Jawa- 
hir, 25,749 feet, since the latter rests on a complete trigonometrical 
measurement (see Herbert and Hodgson in the Asiat. Res., vol. xiv., 
p. 189, and Suppl. to Encycl. Brit., vol. iv., p. 643). I have shown 
elsewhere {Ann. des Sciences Naturelles, Mars, 1825) that the height of 
the Dhawalagiri (28,074 feet) depends on several elements that have 
not been ascertained with certainty, as azimuths and latitudes (Hum- 
boldt, Asie Centrale, t. iii., p. 282). It has been believed, but without 
foundation, that in the Tartaric chain, north of Thibet, opposite to the 
chain of Kuen-lun, there are several snowy summits, whose elevation 
is about 30,000 English feet (almost twice that of Mont Blanc), or, at 
any rate, 29,000 feet (see Captain Alexander Gerard's and John Gerard's 
J(>- '•ney to the Boorendo Pass, 1840, vol. i., p. 143 and 311). Chimbo- 
ru-^o is spoken of in the text only as one of the highest summits of the 
chain of the Andes; for in the year 1827, the learned and highly-gifted 
traveler, Pentland, in his memorable expedition to Upper Peru (Bolivia), 
measured the elevation of two mountains situated to the east of Lake 
Titicaca, viz., the Sorata, 25,200 feet, and the Illimani, 24,000 feet, both 
greatly exceeding th« height of Chimborazo, which is only 21,421 feet, 
and being nearly equal in elevation to the Jawahir, which is the highest 
mouutaia in the Himalaya that has as yet been accurately measured. 



INTRODUCTION. 29 

not have attained to the height of that great Colossus of the 
Andes, the Chimhorazo, whose height is twice that of Mount 
^tna; and we must pile the Righi, or Mount Athos, on the 
summit of the Chimhorazo, in order to form a just estimate 
of the elevation of the Dhawalagiri, the highest point of the 
Himalaya. But although the mountains of India greatly sur- 
pass the Cordilleras of South America hy their astonishing el- 
evation (which, after heing long contested, has at last been 
confirmed by accurate measurements), they can not, from their 
geographical position, present the same inexhaustible variety 
of phenomena by which the latter are characterized. The 
impression produced by the grander aspects of nature does not 
depend exclusively on height. The chain of the Himalaya is 
placed far beyond the limits of the torrid zone, and scarcely is 
a solitary palm-tree to be found in the beautiful valleys of 
Kumaoun and Garhwal.* On the southern slope of the an- 
cient Paropamisus, in the latitudes of 28^ and 34°, nature no 
longer displays the same abundance of tree-ferns and arbores- 
cent grasses, heliconias and orchideous plants, which in tropic- 

Thus Mont Blanc is 5646 feet below Chimborazo ; Chimhorazo, 3770 
feet below the Sorata ; the Sorata, 549 feet below the Jawahir, and prob 
ably about 2880 feet below the Dhawalagiri. According to a new 
measurement of the Illimani, by Pentland, in 1838, the elevation of this 
mountain is given at 23,868 feet, varying only 133 feet from the meas- 
urement taken in 1827. The elevations have been given in this note 
with minute exactness, as erroneous numbers have been introduced 
into many maps and tables recently published, owing to incorrect re- 
ductions of the measux'ements. 

[In the preceding note, taken from those appended to the Introduc- 
tion in the French translation, rewritten by Humboldt himself, the 
measurements are given in meters, but these have been convei'ted into 
English feet, for the greater convenience of the general reader.] — Tr. 

* The absence of palms and tree-ferns on the temperate slopes of the 
Himalaya is shown in Don's Flora Nepalensis, 1825, and in the remark- 
able series of lithographs of WalUch's Flora Indica, whose catalogue 
contains the enormous number of 7683 Himalaya species, almost all 
phanerogamic plants, which have as yet been but imperfectly classified. 
In Nepaul (lat. 26^° to 27^°) there has hitherto been observed only one 
species of palm, Chamaerops martiana, Wall. {Plaidce Asiat., lib. iii., p 
5, 211), which is found at the height of 5250 English feet above the level 
of the sea, in the shady valley of Bunipa. The magnificent tree-fern, 
Alsophila bmnoniaua, Wall, (of which a stem 48 feet long has been in 
the possession of the British Museum since 1831), does not grow in Ne- 
paul, but is found on the mountains of Silhet, to the northwest of Cal- 
cutta, in lat. 24° 50'. The Nepaul fern, Paranema'cyathoides, Don, 
formerly known as Sphaeroptera barbata, Wall. {Plantce Asiat., lib. i., 
p. 42, 48). is, indeed, nearly related to Cyathea, a species of which I 
have seen in the South American Missions of Caripe, measm-ing 33 feet 
in height; this is not, however, properly speaking, a tree. 



30 CO&MOS. 

al regions are to be found even on the highest plateaux of the 
mountains. On the slope of the Himalaya, under the shade 
of the Deodora and the broad-leaved oak, peculiar to these 
Indian Alps, the rocks of granite and of mica schist are cov- 
ered with vegetable forms almost similar to those which char- 
acterize Europe and Northern Asia. The species are not 
identical, but closely analogous in aspect and physiognomy, as, 
for instance, the juniper, the alpine birch, the gentian, the 
marsh parnassia, and the prickly species of Ribes.* The 
chain of the Himalaya is also wanting in the imposing phe- 
nomena of volcanoes, which in the Andes and in the Indian 
Archipelago often reveal to the inhabitants, under the most 
terrific forms, the existence of the forces pervading the inte- 
rior of our planet. 

Moreover, on the southern declivity of the Himalaya, where 
the ascending current deposits the exhalations rising from a 
vigorous Indian vegetation, the region of perpetual snow be- 
gins at an elevation of 11,000 or 12,000 feet above the level 
of the sea,t thus setting a limit to the development of organic 

** Ribes iiubicola, R. glaciale, R. grossularia. The species which 
compose the vegetation of the Himalaya are four pines, notwithstanding 
the assertion of the ancients regarding Eastern Asia (Strabo, lib. 11, p. 
510, Cas.), twenly-five oaks, four birches, two chestnuts, seven maples, 
twelve willows, fourteen roses, three species of strawberry, seven spe- 
cies of Alpine roses (rhododendra), one of which attains a height of 20 
feet, and many other northern genera. Large white apes, having black 
faces, inhabit the wild chestnut-tree of Kashmir, which grows to a height 
of 100 feet, in lat. 33° (see Carl von HUgel's Kasckmir, 1840, 2d pt. 
249). Among the Coniferae, we find the Pinus deodwara, or deodara 
(in Sanscrit, dewa-dar^i, the timber of the gods), which is nearly allied 
to Pinus cedrus. Near the limit of perpetual snow flourish the large 
and showy flowers of the Gentiana venusta, G. Moorcroftiaua, Swertia 
purpurescens, S. speciosa, Parnassia armata, P. nubicola, Poeonia Emo- 
di, Tulipa stellata; and, besides varieties of European genera peculiar 
to these Indian mountains, true European species, as Leontodon tarax- 
acum, Prunella vulgaris, Galium aparine, and Thlaspi arvense. The 
heath mentioned by §aunders, in Turner's Travels, and which had been 
confounded with Calluna vulgaris, is an Andromeda, a fact of the great- 
est importance in the geography of Asiatic plants. If I have made use, 
in this work, of the uuphilosophical expressions of Ejiropean genera, 
European species, growing wild in Asia, &c., it has been in consequence 
of the old botanical language, which, instead of the idea of a large dis- 
semination, or, rather, of the coexistence of organic productions, has 
dogmatically substituted the false hypothesis of a migration, which, 
fi'om predilection*for Europe, is further assumed to have been from west 
to east, 

t On the southern declivity of the Himalaya, the limit of perpetual 
Buow is 12,978 feet above the level of the sea; on the northern decliv- 
ity, or, rather, on the peaks which rise above the Thibet, or Tartarian 



INTKUIJUCIION. 3) 

ahi in a zone that is nearly 3000 feet lower than that to which 
it attains in the equinoctial region of the Cordilleras. 

plateau, this limit is at 16,625 feet from 20^° to 32° of latitude, whilt 
Bt the equator, iu the Andes of Quito, it is 15,790 feet. Such is the 
resuh I have deduced from the combiuatiou of numerous data famished 
by Webb, Gerard, Herbert, and Moorcroft. (See my two memoirs on 
the mountains of India, in 1816 and 1820, iu the Ann. de CJdmie et di 
Physique, t. iii., p- 303 ; t. xiv., p. 6, 22, 50.) The greater elevation to 
which the Hmit of perpetual snow recedes on the Tartarian declivity 
is owing to tlie radiation of heat from the neighboring elevated plains, 
to tlie purity of the atmosphere, and to the infrequent formation of snow 
in an air which is both very cold and veiy dry. (Humboldt, Asie Cen 
trale, t. iii., p. 281-326.) My opinion on the ditference of height of 
the snow-line on the two sides of the Himalaya has the high authority 
of Colebrooke in its favor. He wrote to me in June, 1824, as follows: 
" I also find, from the data in my possession, that the elevation of the 
iiue of perpetual snow is 13,000 feet. On the southern declivity, and 
at latitude 31*^, Webb's measurements give me 13,500 feet, consequently 
500 i'eet more than the height deduced from Captain Hodgson's oh 
servations. Gerard's measurements fully confirm your opinion tha' 
the hue of snow is higher on the northern than on the southern side.' 
<t was not until the present year (1840) that we obtained the complett 
and collected journal of the brothers Gerard, published under the su 
pervision of Mr. Lloyd. {Narrative of a Journey from Caionpoor h 
the Boorendo Pass, in the Himalaya, by Captain Alexander Gerard ant 
John Gerard, edited by George Lloyd, vol. i., p. 291, 311, 320, 327, an< 
^Ml.) Many interesting details regarding some localities may be fount ■ 
in tlie narrative of A Visit to the Shatool,for the Ptirpose of determinin. 
the Line of Perpetual Stiow on the southern face of the Himalaya, in At 
gust, 1822. Unfortunately, however, these travelers always confoun 
the elevation at which sporadic snow falls with the maximum of th 
height that the snow-line attains on the Thibetian plateau. Captaii 
Gerard distinguishes between the summits that rise in the middle o 
the plateau, where he states the elevation of the snow-line to be b( 
*ween 18,000 and 19,000 feet, and the northern slopes of the chain o 
»he Himalaya, which border on the defile of the Sutledge, and can ri 
diate but little heat, owing to the deep ravines with which they ai ^ 
intersected. The elevation of the village of Tangno is given at onl » 
9300 feet, while that of the plateau surrounding the sacred lake of Mj. 
nasa is 17,000 feet. Captain Geraixl finds the snow^-line 500 feet lowt >. 
on the northern slopes, where the chain of the Himalaya is broke i 
through, than toward the southern declivities facing Hindostan, and h • 
'.here estimates the line of perpetual snow at 15,000 feet. The moi 
striking difierences are presented between the vegetation on the Thil 
etian plateau and that characteristic of the southern slopes ot the Hin 
alaya. On the latter the cultivation of grain is arrested at 9974 fee. 
and even there the corn has often to be cut when the blades are sti., 
green. The extreme limit of forests of tali oaks and deodars is 11,900 
feet ; that of dwarf birches, 12,983 feet. On the plains. Captain Gerard 
found pastures up to the height of 17,000 feet; the cereals will grow ui 
14,100 feet, or even at 18,540 feet; birches with tall stems at 14,100 
feet, and copse or brush wood applicable for fuel is found at an elevti 
tioa of upward of 17,000 feet, that is to say, 1280 feet above the lowej 
limits of the snow-line at the equator, in the province of Quito. It is- 



H2 cosMv s. 

But the countries bordering on the equator possess anoihei 
advantage, to which sufficient attentign has not hitherto been 

very desirable that the mean elevation of the Thibetiaii plateau, which 
I have estimated at ouly about 8200 feet between the Himalaya and 
the Kuen-lun, and the difference in the height of the line of perpetual 
snow on the southern and on the northern slopes of the Himalaya, should 
be again ihvestigated by travelers who are accustomed to judge of the 
general conformation of the land. Hitherto simple calculations have too 
often been confounded with actual measurements, and the elevations 
of isolated summits with that of the surrounding plateau. (Compare 
Carl Zimmerman's excellent Hypsometrical Kemarks in his Geograph- 
isclien Analyse der Karte von Inner Asien, 1841, s. 08.) Lord draws 
attention to the difference presented by the two faces of the Himalaya 
and those of the Alpine chain of Hindoo-Coosh, with respect to the 
limits of the snow-line. " The latter chain," he says, "has the table- 
land to the south, in consequence of which the snow-line is higher on 
the southern side, contrary to what we find to be the case with respect 
to the Himalaya, which is bounded on the south by sheltered plains, 
as Hindoo-Coosh is on the north." It must,hov/ever,be admitted that 
the hypsometrical data on which these statements are based require a 
critical revision with regard to several of their details; but still they 
sufSce to establish the main fact, that the remarkable configuration of 
the laud in Central Asia affords man all that is essential to the mainte- 
nance of life, as habitation, food, and fuel, at an elevation above the 
level of the sea which in almost all other parts of the globe is covered 
with perpetual ice. We must except the very dry districts of Bolivia, 
where snow is so rarely met with, and where Pentland (in 1838) fixed 
the snov/-line at 15,667 feet, between 16° and 17|° south latitude. The 
opinion that I had advanced regarding the difference in the snow-line 
on the two faces of the Himalaya has heen most fully confirmed by the 
barometrical observations of Victor Jacquemont, who fell an early sac- 
I'ifice to his noble and unwearied ardor. (See his Correspondanc& 
pendant son Voyage dans V Inde, 1828 a 1832, hv. 23, p. 290, 296,299.) 
" Perpetual snow," says Jacquemont, " descends lower on the southern 
than on the northern slopes of the Himalaya, and the limit constantly? 
rises as we advance to the north of the chain bordering on India. On 
the Kioubrong, about 18,317 feet in elevation, according to Captain 
Gerard, I was still considerably below the limit of perpetual snow, 
which I believe to be 19,690 feet in this part of Hindostan." (This 
estimate I consider much too high.) 

The same ti-aveler says, " To whatever height we rise on the south- 
ern declivity of the Himalaya, the climate retains the same character, 
and the same division of the seasons as in the plains of India ; the sum- 
mer solstice being eveiy year marked by the same prevalence of rain, 
w^hich continues to fall without intermission until the autumnal equi- 
nox. But a new, a totally different climate begins at Kashmir, whose 
elevation I estimate to be 5350 feet, nearly equal to that of the cities 
of Mexico and Popayan" {Correspond, de Jacquemont, t. ii., p. 58 et 74), 
The warm and humid air of the sea, as Leopold von Buch well observes, 
is carried by the monsoons across the plains of India to the skirts of 
the Himalaya, which arrest its couise, and hinder it from diverging to 
the Thibetian districts of Ladak and Lassa. Carl von HUgel estimates 
the elevation of the Valley of Kashmir above the level of the sea at 
5818 feet, and bases his observation on the determination of the boiling 



INTRODUCTION. 33 

directed. This portion of the surface of the globe affords in 
the smallest space the greatest possible variety of impressions 
from the contemplation of nature. Among the colossal mount- 
ains of Cundinamarca, of Quito, and of Peru, furrowed by 
deep ravines, man is enabled to contemplate alike all the fam- 
ilies of plants, and all the stars of the firmament. There, at 
a single glance, the eye surveys majestic palms, humid forests 
of bambusa, and the varied species of Musacese, while above 
these forms of tropical vegetation appear oaks, medlars, the 
sweet-brier, and umbelliferous plants, as in our European 
homes. There, as the traveler turns his eyes to the vault of 
heaven, a single glance embraces the constellation of the South- 
ern Cross, the Magellanic clouds, and the guiding stars of the 
constellation of the Bear, as they circle round the arctic pole. 
There the depths of the earth and the vaults of heaven dis- 
play all the richness of their forms and the variety of their 
phenomena. There the different climates are ranged the one 
above the other, stage by stage, like the vegetable zones, whose 
succession they limit ; and there the observer may readily 
trace the laws that regulate the diminution of heat, as they 
stand indelibly inscribed on the rocky walls and abrupt decliv- 
ities of the Cordilleras. 

Not to M'-eary the reader with the details of the phenomena 
which I long since endeavored graphically to represent,* I 
will here limit myself to the consideration of a few of the gen- 
eral results whose combination constitutes the i^liy^ical delhie- 
ation of the torrid zone. That which, m the vagueness of our 

point of water (see theil 11, s. 155, and Journal of Geog. Soc, vol. vi., 
p. 215). In this valley, where the atmosphere is scarcely ever agita- 
ted by storms, and in 34° 7' lat., snow^ is found, several feet in thick- 
ness, from December to March. 

* See, generally, my Essai sur la Geographie des Plantes, et le Ta- 
bleau physique des Regions Equinoxiales, 1807, p. 80-88. On the diur- 
nal and nocturnal variations of temperatui'e, see Plate 9 of my Atlas 
Geogr. et Phys. du Nouveau Continent; and the Tables in my work, 
entitled De distributione Geographica Plantarum, secundum cosli tempe- 
riem, et altitudinem Montium, 1817, p. 90-116 ; the meteorological por- 
tion of my Asie Centrale, t. iii., p. 212, 224; and, finally, the more 
receut and far more exact exposition of the variations of temperature 
experienced in correspondence with the increase of altitude on the chain 
of the Andes, given in Boussiugault's Memoir, Sur la profondeur a la- 
quelle on trouve, sous les Tropiques, la coucke de Temperature Invaria- 
ble. (Ann. de Chimie et de Physique, 1833, t. liii., p. 225-247.) This 
treatise contains the elevations of 128 points, included between the 
level of the sea and the declivity of the Antisana (17,900 feet), as well 
as the mean temperature of the atmosphere, which varies with the 
height between 81° and 35° F. 

B2 



34 COSMOS. 

impressions, loses all distinctness of form, like some distant 
mountain shrouded from view by a vail of mist, is clearly re- 
vealed by the light of mind, which, by its scrutiny into the 
causes of phenomena, learns to resolve and analyze their dif- 
ferent elements, assigning to each its individual character. 
Thus, in the sphere of natural investigation, as in poetry and 
painting, the delineation of that which appeals most strong- 
ly to the imagination, derives its collective interest from the 
vivid truthfulness with which the individual features are por- 
trayed. 

The regions of the torrid zone not only give rise to the 
most powerful impressions by their organic richness and their 
abundant fertility, but they likewise afford the inestimable 
advantage of revealing to man, by the uniformity of the vari- 
ations of the atmosphere and the development of vital forces, 
and by the contrasts of climate and vegetation exhibited at 
different elevations, the invariability of the laws that regulate 
the course of the heavenly bodies, reflected, as it were, in ter- 
restrial phenomena. Let us dwell, then, for a few moments, 
on the proofs of this regularity, which is such that it may be 
submitted to numerical calculation and computation. 

In the burning plains that rise but little above the level of 
the sea, reign the families of the banana, the cycas, and the 
palm, of wliich the number of species comprised in the flora 
of tropical regions has been so wonderfully increased in the 
present day by the zeal of botanical travelers. To these 
groups succeed, in the Alpine valleys, and the humid and 
shaded clefts on the slopes of the Cordilleras, the tree-ferns, 
whose thick cylindrical trunks and delicate lace-like foliage 
stand out in bold relief against the azure of the sky, and the 
cinchona, from which we derive the febrifuge bark. The 
medicinal strength of this bark is said to increase in propor- 
tion to the degree of moisture imparted to the foliage of the 
tree by the light mists which form the upper surface of the 
clouds resting over the plains. Every where around, the con- 
fines of the forest are encircled by broad bands of social plants, 
as the delicate aralia, the thibaudia, and the myrtle-leaved 
Andromeda, while the Alpine rose, the magnificent befaria, 
weaves a purple girdle round the spiry peaks. In the cold 
regions of the Paramos, which is continually exposed to the 
fury of storms and winds, we find that flowering shrubs and 
herbaceous plants, bearing large and variegated blossoms, 
h^ve given place to monocotyledons, whose slender spikes con- 
it"*,ute the sole covering of the soil. This is the zone of the 



INTRODUCTION. 35 

glasses, one vast savannah extending over the immense mount- 
ain- plateaux, and reflecting a yellow, almost golden tinge, tc 
the slopes of the Cordilleras, on which graze the lama and the 
cattle domesticated by the European colonist. Where the 
naked trachyte rock pierces the grassy turf, and penetrates into 
those higher strata of air which are supposed to be less charged 
with carbonic acid, we meet only with plants of an inferior or- 
ganization, as lichens, lecideas, and the brightly-colored, dust- 
like lepraria, scattered around in circular patches. Islets of 
fresh-fallen snow, varying in form and extent, arrest the last 
feeble traces of vegetable development, and to these succeeds 
the region of perpetual snow, whose elevation undergoes but 
little change, and may be easily determined. It is but rarely 
that the elastic forces at work within the interior of our globe 
have succeeded in breaking through the spiral domes, which, 
resplendent in the brightness of eternal snow, crown the sum- 
mits of the Cordilleras ; and even where these subterranean 
forces have opened a permanent communication with the at- 
mosphere, through circular craters or long fissures, they rarelj 
send forth currents of lava, but merely eject ignited scoriae, 
steam, sulphureted hydrogen gas, and jets of. carbonic acid. 

In the earhest stages of civilization, the grand and imposing 
spectacle presented to the minds of the inhabitants of the trop- 
ics could only awaken feelings of astonishment and awe. Il 
might, perhaps, be supposed, as we have already said, that the 
periodical return of the same phenomena, and the uniform man- 
ner in which they arrange themselves in successive groups, 
would have enabled man more readily to attain to a knowl- 
edge of the laws of nature ; but, as far as tradition and history 
guide us, we do not find that any application was made of the 
advantages presented by these favored regions. Recent re- 
searches have rendered it very doubtful whether the primitive 
seat of Hindoo civihzation — one of the most remarkable phase.' 
in the progress of mankind — was actually within the tropics 
Airyana Vaedjo, the ancient cradle of the Zend, was situatec 
to the northwest of the upper Indus, and after the great re 
ligious schism, that is to say, after the separation of the Ir:i 
uians from the Brahminical institution, the language that ha« 
previously been common to them and to the Hindoos assume' 
among the latter people (together with the hterature, habit: 
and condition of society) an individual form in the Magodha oi 
Madhya Desa,* a district that is bounded" by the great chaii. 

* See, on the Madhjadecja, properly so called, Lassen's exceilei 
work, entitled Indische Altcrthumskun'de, bd. i., s. 92. The Chinest 



S6 cosivros. 

oi' Himalaya and the smaller range of the Vindhya. In less 
ancient times the Sanscrit language and civilization advanced 
tovi^ard the southeast, penetrating further within the torrid zone, 
as my brother Wilhelm von Humboldt has shov^^n in his great 
work on the Kavi and other languages of analogous structure.* 

Notwithstanding the obstacles opposed in northern latitudes 
to the discovery of the laws of nature, owing to the excessive 
complication of phenomena, and the perpetual local variations 
that, in these climates, afiect the movements of the atmosphere 
and the distribution of organic forms, it is to the inhabitants 
of a small section of the temperate zone that the rest of man- 
kind owe the earliest revelation of an intimate and rational 
acquaintance with the forces governing the physical world. 
Moreover, it is from the same zone (which is apparently more 
favorable to the progress of reason, the softening of manners, 
and the security of public liberty) that the germs of civiliza- 
tion have been carried to the regions of the tropics, as much 
by the migratory movement of races as by the establishment 
of colonies, differing widely in their institution from those of 
the Phoenicians or Greeks. 

In speaking of the influence exercised by the succession of 
phenomena on the greater or lesser facility of recognizing the 
causes producing them, I have touched upon that important 
stage of our communion with the external world, when the en- 
joyment arising from a knowledge of the laws, and the mutual 
connection of phenomena, associates itself with the charm of 
a simple contemplation of nature. That which for a long 
time remains merely an object of vague intuition, by degrees 
acquires the certainty of positive truth ; and man, as an im- 
mortal poet has said, in our own tongue — Amid ceaseless 
change seeks the unchanging pole.f 

In order to trace to its primitive source the enjoyment de- 
rived from the exercise of thought, it is sufficient to cast a 
J:apid glance on the earliest dawnings of the philosophy of na- 
ture, or of the ancient doctrine of the Cosmos. We find even 

give the name of Mo-kie-thi to the southern Bahar, situated to the 
south of the Ganges (see Foe-Koue-Ki, by Chy-Fa-Hian, 1836, p. 256). 
Djambu-dwipa is the name given to the whole of India; but the words 
also indicate one of the four Buddhist continents. 

* Ueber die Kawi Sprache aiif der Insel Java, nebst einer Einleiijinff 
iiber die Verschiedenheit des menschlichen Spra^'hbaiies und ihren Ein 
fluss auf die geistige Entwickelung des Mensckengeschlechf s, von Wil 
helm V. Humboldt, 1836, bd. i., s. 5-510. 

t This verse occurs in a poem of Schiller, entitled Der Spaziergayig 
which first appeared in 1795, in the Horen. 



INTRODUCTION. 37 

among the most savage nations (as my own travels enable me 
to attest) a certain vague, terror-stricken sense of the all-pow- 
erful unity of natural forces, and of the existence of an invisi- 
ble, spiritual essence manifested in these forces, whether in 
unfolding the flower and maturing the fruit of the nutrient 
tree, in upheaving the soil of the forest, or in rending the clouds 
with the might of the storm. We may here trace the revela- 
tion of a bond of union, linking together the visible world and 
that higher spiritual world which escapes the grasp of the 
senses. The two become unconsciously blended together, de- 
veloping in the mind of man, as a simple product of ideal con- 
ception, and independently of the aid of observation, the first 
germ of a Fhiloioiohy of Nature. 

Among nations least advanced in civilization, the imagina- 
tion revels in strange and fantastic creations, and, by its pre- 
dilection for symbols, alike influences ideas and language. In- 
stead of examining, men are led to conjecture, dogmatize, and 
interpret supposed facts that have never been observed. The 
inner world of thought and of feelins: does not reflect the imajje 
of the external world in its primitive purity. That which in 
some regions of the earth manifested itself as the rudiments 
of natural philosophy, only to a small number of persons en- 
dowed with superior inteUigence, appears in other regions, and 
among entire races of men, to be the result of mystic tenden- 
cies and instinctive intuitions. An intimate communion with 
nature, and the vivid and deep emotions thus awakened, are 
likewise the source from which have sprung the first impulses 
toward the worship and deification of the destroying and pre- 
serving forces of the universe. But by degrees, as man, after 
having passed through the different gradations of intellectual 
development, arrives at the free enjo}rment of the regulating 
power of reflection, and learns by gradual progress, as it were, 
to separate the world of ideas from that of sensations, he no 
longer rests satisfied merely with a vague presentiment of the 
harmonious unity of natural forces ; thought begins to fulfill 
its noble mission ; and observation, aided by reason, endeav- 
ors to trace phenomena to the causes from which they spring 

The history of science teaches us the difficulties that have 
opposed the progress of this active spirit of inquiry. Inaccu 
rate and imperfect observations have led, by false inductions, 
to the great number of physical views that have been perpet- 
uated as popular prejudices among all classes of society. Thus 
by the side of a solid and scientific knowledge of natural phe- 
nomena there has been preserved a system of the pretended 



38 COSMOS. 

results of observation, which is so much the more difficult to 
shake, as it denies the vahdity of the facts by which it may 
be refuted. This empiricism, the melancholy heritage trans- 
mitted to us from former times, invariably contends for the 
truth of its axioms with the arrogance of a narrow-minded 
spirit. Physical philosophy, on the other hand, when based 
upon science, doubts because it seeks to investigate, distin- 
guishes between that which is certain and that which is mere- 
ly probable, and strives incessantly to perfect theory by ex- 
tending the circle of observation. 

This assemblage of imperfect dogmas, bequeathed by one- 
age to another — this physical philosophy, which is composed 
of popular prejudices — is not only injurious because it perpet- 
uates error with the obstinacy engendered by the evidence of 
ill-observed facts, but also because it hinders the mind from 
attaining to higher views of nature. Instead of seeking to 
discover the mean or medium point, around which oscillate, 
in apparent iiidependence offerees, all the phenomena of the 
external world, this system delights in multiplying exceptions 
to the law, and seeks, amid phenomena and in organic forms, 
for something beyond the marvel of a regular succession, and 
an internal and progressive development. Ever inclined to 
beheve that the order of nature is disturbed, it refuses to rec 
ognize in the present any analogy with the past, and, guided 
by its own varying hypotheses, seeks at hazard, either in the 
interior of the globe or in the regions of space, for the cause 
of these pretended perturbations. 

It is the special object of the present work to combat those 
errors which derive their source Irom a vicious empiricism and 
from imperfect inductions. The higher enjoyments yielded by 
the study of nature depend upon the correctness and the depth 
of our views, and upon the extent of the subjects that maybe 
comprehended in a single glance. Increased mental cultiva- 
tion has given rise, in all classes of society, to an increased de- 
sire of embellishing life by augmenting the mass of ideas, and 
by multiplying means for their generalization ; and this sen- 
timent fully refutes the vague accusations advanced against 
the age in which we live, showing that other interests, be- 
sides the material wants of life, occupy the minds of men. 

It is almost with reluctance that I am about to speak of a 
sentiment, which appears to arise from narrow-minded views, 
or from a certain weak and morbid sentimentality — I alludo 
to thejTear entertained by some persons, that nature rnay by 
degrees lose a portion of the charm and magic of her power. 



INTRODUCTION. 39 

4S we learn more and more how to nnvail her secrets, com- 
prehend the mechanism of the movements of the heavenly 
bodies, and estimate numerically the intensity of natural forces. 
It is true that, properly speaking, the forces of nature can only 
exercise a magical power over us as long as their action is 
ehrouded in mystery and darkness, and does not admit of be- 
mg classed among the conditions with which experience has 
made us acquainted. The effect of such a power is, there- 
fore, to excite the imagination, but that, assuredly, is not the 
faculty of mind we would evoke to preside over the laborious 
and elaborate observations by which we strive to attain to a 
knowledge of the greatness and excellence of the laws of the 
universe. 

The astronomer who, by the aid of the heliometer or a 
double-refracting prism,* determines the diameter of planetary 
bodies ; who measures patiently, year after year, the meridian 
altitude and the relative distances of stars, or who seeks a tel 
escopic comet in a group of nebulae, does not feel his imagina- 
tion more excited — and this is the very guarantee of the pre- 
cision of his labors — than the botanist who counts the divi- 
sions of the calyx, or the number of stamens in a flower, or ex- 
amines the connected or the separate teeth of the peristoma 
surrounding the capsule of a moss. Yet the multiplied an- 
gular measurements on the one hand, and the detail of organic 
relations on the other, alike aid in preparing the way for the 
attainment of higher views of the laws of the universe. 

We must not confound the disposition of mind in the ob- 
server at the time he is pursuing his labors, with the ulterior 
greatness of the views resulting from investigation and the 
exercise of thought. The physical philosopher measures with 
admirable sagacity the waves of light of unequal length which 
by interference mutually strengthen or destroy each other, 
even with respect to their chemical actions ; the astronomer, 
armed with powerful telescopes, penetrates the regions of 
space, contemplates, on the extremest confines of our solar 
system, the satellites of Uranus, or decomposes faintly spark- 
ling points into double stars differing in color. The botanist 
discovers the constancy of the gyratory motion of the chara in 
the greater number of vegetable cells, and recognizes in the 
genera and natural families of plants the intimate relations 
of organic forms. The vault of heaven, studded with nebu- 

* Arago's ocular micrometer, a happy improvement upon Rochou'a 
prismatic or double-refraction micrometer. See M. Mathieu's note ii 
Delambre's Histoire de V Astronomic au dix-huUieme Siecle, 1827. 



40 COSMOS 

IsL' and stars, and the rich vegetable mantle that covers the 
soil in the climate of palms, can not surely fail to produce on 
the minds of these laborious observers of nature an impression 
more imposing and more w^orthy of the majesty of creation 
than on those who are unaccustomed to investigate the great 
mutual relations of phenomena. I can not, therefore, agree 
with Burke when he says, "it is our ignorance of natural 
things that causes all our admiration, and chiefly excites our 
passions." 

While the illusion of the senses would make the stars sta- 
tionary in the vault of heaven. Astronomy, by her aspiring la- 
bors, has assigned indefinite bounds to space ; and if she have 
set limits to the great nebula to which our solar system be- 
longs, it has only been to show us in those remote regions of 
space, which appear to expand in proportion to the increase 
of our optic powers, islet on islet of scattered nebulce. The 
feeling of the sublime, so far as it arises from a contemplation 
of the distance of the stars, of their greatness and physical ex- 
tent, reflects itself in the feeling of the infinite, which belongs 
to another sphere of ideas included in the domain of mind. 
The solemn and imposing impressions excited by this senti- 
ment are owing to the combination of which we have spoken, 
and to the analogous character of the enjoyment and emotions 
awakened in us, whether we float on the surface of the great 
deep, stand on some lonely mountain summit enveloped in the 
half transparent vapory vail of the atmosphere, or by the aid 
of powerful optical instruments scan the regions of space, and 
see the remote nebulous mass resolve itself into worlds of stars. 

The mere accumulation of unconnected observations of de- 
tails, devoid of generalization of ideas, may doubtlessly have 
tended to create and foster the deeply-rooted prejudice, that 
the study of the exact sciences must necessarily chill the feel- 
ings, and diminish the nobler enjoyments attendant upon a 
contemplation of nature. Those who still cherish such erro 
neous views in the present age, and amid the progress of pub- 
lic opinion, and the advancement of all branches of knowledge, 
fail in duly appreciating the value of every enlargement of th(; 
sphere of intellect, and the importance of the detail of isolated 
facts in leading us on to general results. The fear of sacri 
ficing the free enjoyment of nature, under the influence of" sci- 
entific reasoning, is often associated with an apprehension 
that every mind may not be capable of grasping the truths 
of the philosophy of nature. It is certainly true that in the 
midst of the universal fluctuation of phenomena and vital 



INTRODUCTION. 41 

forces — ill that inextricable net- work of organisms by turns 
developed and destroyed — each step that we make in the 
more intimate knowledge of nature leads us to the entrance 
of new labyrinths ; but the excitement produced by a presenti- 
ment of discovery, the vague intuition of the mysteries to be 
unfolded, and the multiplicity of the paths before us, all tend 
to stimulate the exercise of thought in every stage of knowl- 
edge. The discovery of each separate law of nature leads to 
the establishment of some other more general law, or at least 
indicates to the intelligent observer its existence. Nature, as 
a celebrated physiologist* has defined it, and as the word was 
interpreted by the Greeks and Romans, is " that which is ever 
growing and ever unfolding itself in new forms." 

The series of organic types becomes extended or perfected 
in proportion as hitherto unknown regions are laid open to our 
view by the labors and researches of travelers and observers ; 
as living organisms are compared with those which have dis- 
appeared in the great revolutions of our planet ; and as micro- 
scopes are made more perfect, and are more extensively and 
efficiently employed. In the midst of this immense variety, 
and this periodic transformation of animal and vegetable pro- 
ductions, we see incessantly revealed the primordial mystery 
of all organic development, that same great problem of meta- 
Tnorpliosis which Gothe has treated with more than common 
sagacity, and to the solution of which man is urged by his 
desire of reducuiEr vital forms to the smallest number of fun- 
damental types. As men contemplate the riches of nature, 
and see the mass of observations incessantly increasing be- 
fore them, they become impressed with the intimate convic- 
tion that the surface and the interior of the earth, the depths 
of the ocean, and the regions of air will still, when thousands 
and thousands of years have passed away, open to the scien- 
tific observer untrodden paths of discovery. The regret of 
Alexander can not be appUed to the progress of observation 
and intelligence.! General considerations, whether they treat 
of the agglomeration of matter in the heavenly bodies, or of 
the geographical distribution of terrestrial organisms, are not 
only in themselves more attractive than special studies, but 
they also afford superior advantages to those who are unable 
to devote much time to occupations of this nature. The dif- 
ferent branches of the study of natural history are only accessi- 
ble in certain positions of social life, and do not, at every sea- 

* Cams, Von den Urtheilen des Knochen und Schalen Gerustes, 18"2^ 
$ 6 + Plut., in Vita Alex. Magni, cap. 7 



42 COSMOS. 

son and m every climate, present like enjoyments. Thus, in 
the dreary regions of the north, man is deprived for a long 
period of the year of the spectacle presented by the activity 
of the productive forces of organic nature ; and if the mind 
be directed to one sole class of objects, the most animated 
narratives of voyages in distant lands w^ill fail to interest and 
attract us, if they do not touch upon the subjects to v^^hich 
we are most partial. 

As the history of nations — if it were always able to trace 
events to their true causes — might solve the ever-recurring 
enigma of the oscillations experienced by the alternately pro- 
gressive and retrograde movement of human society, so might 
also the physical description of the world, the science of the 
Co&inos, if it were grasped by a powerful intellect, and based 
upon a knowledge of all the results of discovery up to a giv- 
en period, succeed in dispelling a portion of the contradictions 
which, at first sight, appear to arise from the complication oi 
phenomena and the multitude of the perturbations simultane- 
ously manifested. 

The knowledge of the laws of nature, whether we can 
trace them in the alternate ebb and flow of the ocean, in the 
measured path of comets, or in the mutual attractions of mul- 
tiple stars, alike increases our sense of the calm of nature, 
while the chimera so long cherished by the human mind in 
its early and intuitive contemplations, the belief in a "discord 
of the elements," seems gradually to vanish in proportion as 
science extends her empire. General views lead us habitu- 
ally to consider each organism as a part of the entire creation, 
and to recognize in the plant or the animal not merely an 
isolated species, but a form linked in the chain of being to 
other forms either living or extinct. They aid us in compre- 
hending the relations that exist between the most recent dis 
coveries and those which have prepared the way for them. 
Although fixed to one point of space, we eagerly grasp at a 
knowledge of that wliich has been observed in different and 
far-distant regions. We delight in tracking the course of the 
bold mariner through seas of polar ice, or in following him to 
the summit of that volcano of the antarctic pole, whose fires 
may be seen from afar, even at mid-day. It is by an ac- 
quaintance with the results of distant voyages that we may 
learn to comprehend some of the marvels of" terrestrial mag- 
netism, and be thus led to appreciate the importance of the 
estal lishments of the numerous observatories which in the 
present day cover both hemispheres, and are designed to note 



INTRODUCTION. 43 

the simullaiieous occurrence of perturbations, and the frequen- 
cy and duration of tnagnetic storms. 

Let me be permitted here to touch upon a few points con- 
nected with discoveries, whose importance can only be esti- 
mated by those who have devoted themselves to the study 
of the physical sciences generally. Examples chosen from 
among the phenomena to which special attention has been 
directed in recent times, will throw additional light upon the 
preceding considerations. Without a preHminary knowledge 
of the orbits of comets, we should be unable duly to appre- 
ciate the importance attached to the discovery of one of these 
bodies, whose elliptical orbit is included in the narrow limits 
of our solar system, and which has revealed the existence of 
an ethereal fluid, tending to diminish its centrifugal force and 
the period of its revolution. 

The superficial half-knowledge, so characteristic of the 
present day, which leads to the introduction of vaguely com- 
prehended scientific views into general conversation, also gives 
rise, under various forms, to the expression of alarm at the 
supposed danger of a collision between the celestial bodies, or 
of disturbance in the climatic relations of our globe. These 
phantoms of the imagination are so much the more injurious 
as they derive their source from dogmatic pretensions to true 
science. The history of the atmosphere, and of the annual 
variations of its temperature, extends already sufficiently far 
back to show the recurrence of shglit disturbances in the 
mean temperature of any given place, and thus afibrds suffi- 
cient guarantee against the exaggerated apprehension of a 
general and progressive deterioration of the climates of Eu- 
rope. Encke's comet, which is one of the three interior 
comets, completes its course in 1200 days, but from the form 
and position of its orbit it is as little dangerous to the earth 
as Halley's great comet, whose revolution is not completed in 
less than seventy-six years (and which appeared less brilliant 
in 1835 than it had done in 1759) : the interior comet of 
Biela intersects the earth's orbit, it is true, but it can only 
approach our globe when its proximity to the sun coincides 
with our winter solstice. 

The quantity of heat received by a planet, and whose un- 
equal distribution determines the meteorological variations 
of its atmosphere, depends alike upon the light-engendering 
force of the sun ; that is to say, upon the conditio-i of its 
gaseous coverings, and upon the relative position of the planet 
and the central body. 



44 COSMOS. 

There are variations, it is true, which, in obedience to the 
laws of universal gravitation, affect the form of the earth's or- 
bit and the inclination of the ecliptic, that is, the angle M^hich 
the axis of the earth makes with the plane of its orbit ; but 
these periodical variations are so slow, and are restricted with- 
in such narrow limits, that their thermic effects would hardly 
be appreciable by our instruments in many thousands of years. 
The astronomical causes of a refrigeration of our globe, and 
of the diminution of moisture at its surface, and the nature 
and frequency of certain epidemics — phenomena which are 
often discussed in the present 4ay according to the benighted 
views of the Middle Ages — ought to be considered as beyond 
the range of our experience in physics and chemistry. 

Physical astronomy presents us with other phenomena, 
which can not be fully comprehended in all their vastness 
without a previous acquirement of general views regarding 
the forces that govern the universe. Such, for instance, are 
the innumerable double stars, or rather suns, which revolve 
round one common center of gravity, and thus reveal in dis- 
tant worlds the existence of the Newtonian law ; the larger 
or smaller number of spots upon the sun, that is to say, the 
openings formed through the luminous and opaque atmosphere 
surrounding the solid nucleus ; and the regular appearance, 
about the 13th of November and the 1 1th of August, of shoot- 
ing stars, which probably form part of a belt of asteroids, in- 
tersecting the earth's orbit, and moving with planetary ve- 
locity. 

Descending from the celestial regions to the earth, we 
would fain inquire into the relations that exist between the 
oscillations of the pendulum in air (the theory of which ha.s 
been perfected by Bessel) and the density of our planet ; and 
how the pendulum, acting the part of a plummet, can, to a 
certain extent, throw light upon the geological constitution 
of strata at great depths 1 By means of this instrument we 
are enabled to trace the striking analogy which exists be- 
tween the formation of the granular rocks composing the 
lava currents ejected from active volcanoes, and those endog- 
enous misses of granite, porphyry, and serpentine, which, is- 
suing from the interior of the earth, have broken, as erup- 
tive rocks, through the secondary strata, and modified them 
by contact, either in rendering them harder by the introduc- 
tion of silex, or reducing them into dolomite, or, finally, by 
inducing within them the formation of crystals of the most 
varied composition. The elevation of sporadic islands, of , 



INTKODUCTtON. 45 

domes of trachyte, and cones of basalt, by the elastic forces 
emanating from the fluid interior of our globe, has led one 
of the first geologists of the age, Leopold von Buch, to the 
theory of the elevation of continents, and of mountain chains 
generally. This action of subterranean forces in breaking 
through and elevating strata of sedimentary rocks, of which 
the coast of Chili, in consequence of a great earthquake, fur- 
nished a recent example, leads to the assumption that the 
pelagic shells found by M. Bonpland and myself on the ridge 
of the Andes, at an elevation of more than 15,000 English 
feet, may have been conveyed to so extraordinary a position, 
not by a rising of the ocean, but by the agency of volcanic 
forces capable of elevating into ridges the softened crust of 
the earth. 

I apply the term volcanic^ in the widest sense of the word, 
to every action exercised by the interior of a planet on its 
external crust. The surface of our globe, and that of the 
moon, manifest traces of this action, which in the former, at 
least, has varied during the course of ages. Those who are 
ignorant of tlio fact that the internal heat of the earth in- 
creases so rapidly with the increase of depth that granite is 
m a state of fusion about twenty or thirty geographical miles 
below the surface,* can not have a clear conception of the 
causes, and the simultaneous occurrence of volcanic eruptions 
at places widely removed from one another, or of the extent 
and intersection of circles of commotion in earthquakes, or of 
the uniformity of temperature, and equality of chemical com- 
position observed in thermal springs during a long course of 
years. The quantity of heat peculiar to a planet is, however, 
a matter of such importance — being the result of its primitive 
condensation, and varying according to the nature and dura- 
tion of the radiation — that the study of this subject may 
throw some degree of light on the history of the atmosphere, 
and the distribution of the organic bodies imbedded in the 
solid crust of the earth. This study enables us to understand 
how a tropical temperature, independent of latitude (that is, 
of the distance from the poles), may have been produced by 
deep fissures remaining open, and exhaling heat from the in- 

* The determinations usually given of the point of fusion are in 
general much too high for refracting substances. According to the very 
accurate researches of Mitscherlich, the melting point of granite can 
hardly exceed 2372° F. 

[Dr. Mantell states in The Wonders of Geology, 1848, vol. i., p. 34, 
that this increase of temperature amounts to 1° of Fahrenheit for eveiy 
fifty-four feet of vertical depth,"} — Tr. 



46 coSxMos. 

terior of the globe, at a period when the earth's crust we^ 
still furrowed and rent, and only in a state of semi-solidifica- 
tion ; and a primordial condition is thus revealed to us, in 
which the temperature of the atmosphere, and climates gen- 
erally, were owing rather to a liberation of caloric and of dif- 
ferent gaseous emanations (that is to say, rather to the ener- 
getic reaction of the interior on the exterior) than to the posi- 
tion of the earth with respect to the central body, the sun. 

The cold regions of the earth contain, deposited in sedi- 
mentary strata, the products of tropical climates ; thus, in 
the coal formations, we find the trunks of palms standing up- 
right amid coniferee, tree ferns, goniatites, and fishes having 
rhomboidal osseous scales ;* in the Jura limestone, colossal 
skeletons of crocodiles, plesiosauri, planulites, and stems of the 
cycadese ; in the chalk formations, small polythalamia and 
bryozoa, whose species still exist in our seas ; in tripoli, or 
polishing slate, in the semi-opal and the farina-like opal or 
mountain meal, agglomerations of siliceous infusoria, which 
have been brought to light by the powerful microscope of 
Ehrenberg;t and, lastly, in transported soils, and in certain 
caves, the bones of elephants, hyenas, and lions. An intimate 
acquaintance with the physical phenomena of the universe 
leads us to regard the products of warm latitudes that are 
thus found in a fossil condition in northern regions not merely 
as incentives to barren curiosity, but as subjects awakening 
deep reflection, and opening new sources of study. 

The number and the variety of the objects I have alluded 
to give rise to the question whether general considerations of 
physical phenomena can be made sufficiently clear to persons 
who have not acquired a detailed and special knowledge of 

* See the classical woik on the fislies of the Old World by Agassiz, 
Reck, sur les Poissons Fossiles, 1834, vol. i., p. 38; vol. ii., p. 3, 28, 
34, App., p. 6. The whole genus of Amblypterus, Ag., nearly allied 
to Palaeouiscus (called also Palueothrissum), lies buried beneath the 
Jura formations in the old carboniferous strata. Scales which, in some 
fishes, as in the family of Lepidoides (ordei* of Ganoides), are formed 
like teeth, and covered in certain pai'ts with enamel, belong, after the 
Placoides, to the oldest forms of fossil fishes ; their living representa- 
tives are still found in two genera, the Bichir of the Nile and Senegal, 
and the Lepidosteus of the Ohio. 

\ [The polishing slate of Bilin is stated by M. Ehrenberg to form a 
series of strata fourteen feet in thickness, entirely made up of the sili- 
ceous shells of GaillonellcB, of such extreme minuteness that a cubic 
inch of the stone contains forty-one thousand millions ! The Bergmehl 
(mountain meal ov fossil farina) of San Flora, in Tuscany, is one mass 
of auimalculites. See the interesting work of G. A Manlell, On Ik^f 
Medals of Creation, vol. i., p. 223.]— jTr. 



INTRODUCTJOX. 47 

descriptive natural history, geology, or mathematical astron- 
omy ? I think we ought to distinguish here between him 
whose task it is to collect the individual details of" various 
observations, and study the mutual relations existing among 
them, and him to whom these relations are to be revealed, 
under the form of general results. The former should be aT5- 
quainted with the specialities of phenomena, that he may ar- 
rive at a generalization of ideas as the result, at least in part, 
of his own observations, experiments, and calculations. It 
can not be denied, that where there is an absence of positive 
knowledge of physical phenomena, the general results which 
impart so great a charm to the study of nature can not all 
be made equally clear and intelligible to the reader, but still 
I venture to hope, that in the work which I am now prepar- 
ing on the physical laws of the universe, the greater part of 
the facts advanced can be made manifest without the neces- 
sity of appealing to fundamental views and principles. The 
picture of nature thus drawn, notmthstanding the want of 
distinctness of some of its outlines, will not be the less able to 
enrich the intellect, enlarge the sphere of ideas, and nourish 
and vivify the imagiuation. 

There is, perhaps, some truth in the accusation advanced 
against many German scientific works, that they 'lessen the 
value of general views by an accumulation of detail, and do 
not sufficiently distinguish between those great results which 
form, as it were, the beacon lights of science, and the long 
series of means by which they have been attained. This 
method of treating scientific subjects led the most illustrious 
of our poets* to exclaim with impatience, " The Germans 
have the art of making science inaccessible." An edifice can 
not produce a striking efTect until the scaffolding is removed, 
that had of necessity been used during its erection. Thus the 
uniformity of figure observed in the distribution of continental 
masses, which all terminate toward the south in a pyramidal 
form, and expand toward the north (a law that determines 
the nature of climates, the direction of currents in the ocean 
and the atmosphere, and the transition of certain types of 
tropical vegetation toward the southern temperate zone), may 
be clearly apprehended without any knowledge of the geo- 
desical and astronomical operations by means of which these 
pyramidal forms of continents have been determiued. In like 
manner, physical geography teaches us by how many leagues 

* Gotlie, iu Die Aphorismen ilbcr NaturwisscJischaft, bd. I., .s, 155 
( Werke kleine Ausgabe, von 1833.) 



48 COSMOS. 

the equatorial axis exceeds the polar axis of the globe, and 
shows us the mean equality of the flattening of the two hemi- 
spheres, without entaiUng on us the necessity of giving the 
detail of the measurement of the degrees in the meridian, or 
the observations on the pendulum, which have led us to know 
that the true figure of our globe is not exactly that of a regu- 
lar ellipsoid of revolution, and that this irregularity is reflect- 
ed in the corresponding irregularity of the movements of the 
moon. 

The views of comparative geography have been specially 
enlarged by that admirable work, Erdkunde im Verhciltniss 
zur Natur und zur Geschichte, in which Carl Emitter so ably 
delineates the physiognomy of our globe, and shows the influ- 
ence of its external configuration on the physical phenomena 
on its surface, on the migrations, laws, and manners of nations, 
and on all the principal historical events enacted upon the face 
of the earth. 

France possesses an immortal work, L' Exjoosition du Sijs- 
te?7ie dtc Monde, in which the author has combined the results 
of the highest astronomical and mathematical labors, and pre- 
sented them to his readers free from all processes of demon- 
stration. The structure of the heavens is here reduced to the 
simple solution of a great problem in mechanics ; yet Laplace's 
work has never yet been accused of incompleteness and want 
of profundity. 

The distinction between dissimilar subjects, and the sepa- 
ration of the general from the special, are not only conducive 
to the attainment of perspicuity in the composition of a phys- 
i'-al history of the universe, but are also the means by which 
a character of greater elevation may be imparted to the study 
of nature. By the suppression of all unnecessary detail, the 
great masses are better seen, and the reasoning faculty is ena- 
bled to grasp all that might otherwise escape the limited range 
of the senses. 

The exposition of general results has, it must be owned, been 
singularly facilitated by the happy revolution experienced since 
•he close of the last century, in the condition of all the special 
sciences, more particularly of geology, chemistry, and descrip- 
t.ive natural history. In proportion as laws admit of more 
.general application, and as sciences mutually enrich each other, 
md by their extension become connected together in more im- 
oierous and more intimate relations, the development of gen- 
eral truths may be given with conciseness devoid of superfici- 
ality. On being first examined, all phenomena appear to be 



INTRODUCTION. 49 

isolated, and it is only by the result of a multiplicity of obser- 
vations, combined by reason, that we are able to trace the 
mutual relations existing between them. If, however, in the 
present age, which is so strongly characterized by a brilliant 
course of scientific discoveries, we perceive a w-ant of connec- 
tion in the phenomena of certain sciences, we may anticipate 
the revelation of new facts, whose importance will probably 
be commensurate with the attention directed to these branches 
of study. Expectations of this nature may be entertained with 
regard to meteorology, several parts of optics, and to radiating 
heat, and electro-magnetism, since the admirable discoveries 
of Melloni and Faraday. A fertile field is here opened to dis- 
covery, although the voltaic pile has already taught us the 
intimate connection existing between electric, magnetic, and 
chemical phenomena. Who will venture to affirm that we 
have any precise knowledge, in the present day, of that part 
of the atmosphere which is not oxygen, or that thousands of 
gaseous substances affecting our organs may not be mixed with 
the nitrogen, or, finally, that we have even discovered the whole 
number of the forces which pervade the universe ? 

It is not the purpose of this essay on the physical history of 
the world to reduce all sensible phenomena to a small number 
of abstract principles, based on reason only. The physical 
history of the universe, whose exposition I attempt to develop, 
does not pretend to rise to the perilous abstractions of a purely 
rational science of nature, and is simply a phydcal geography, 
combined icith a descrijotion of the regions of space and the 
bodies occujnjing them. Devoid of the profoundness of a purely 
speculative philosophy, my essay on the Cos^nos treats of the 
contemplation of the universe, and is based upon a rational 
empiricism, that is to say, upon the results of the facts regis- 
tered by science, and tested by the operations of the intellect. 
It is within these limits alone that the work, which I now 
venture to undertake, appertains to the sphere of labor to 
which I have devoted myself throughout the course of my 
long scientific career. The path of inquiry is not unknown 
to me, although it may be pursued by others with greater 
success. The unity which I seek to attain in the development 
of the great phenomena of the universe is analogous to that 
which historical composition is capable of acquiring. All 
points relating to the accidental individuahties, and the essen- 
tial variations of the actual, whether in the form and arrange- 
ment of natural objects in the struggle of man against the 
elements, or of nations against nations, do not admit of being 

Vol. I— C 



50 COSMOS. 

based only on a rational foundation — that is to say, of being 
deduced from ideas alone. 

It seems to me that a like degree of empiricism attaches to 
the Description of the Universe and to Civil History ; but in 
reflecting upon physical phenomena and events, and tracing 
their causes by the process of reason, we become more and 
more convinced of the truth of the ancient doctrine, that the 
forces inherent in matter, and those which govel'n the moral 
world, exercise their action under the control of primordial 
necessity, and in accordance with movements occurring period- 
ically after longer or shorter intervals. 

It is this necessity, this occult but permanent connection, 
this periodical recurrence in the progressive development of 
forms, phenomena, and events, which constitute nature, obe- 
dient to the first impulse imparted to it. Physics, as the term 
signifies, is limited to the explanation of the phenomena of the 
material world by the properties of matter. The ultimate 
object of the experimental sciences is, therefore, to discover 
laws, and to trace their progressive generalization. All that 
exceeds this goes beyond the province of the physical descrip- 
tion of the universe, and appertains to a range of higher spec- 
ulative views. 

Emanuel Kant, one of the few philosophers who have es- 
caped the imputation of impiety, has defined with rare sagac- 
ity the limits of physical explanations, in his celebrated essay 
On the Theory and Strncture of the Heaven?,, published at 
Konigsberg in 1755. 

The study of a science that promises to lead us through the 
vast range of creation may be compared to a journey in a far- 
distant land. Before w^e set forth, we consider, and often 
with distrust, our own strength, and that of the guide we have 
chosen. But the apprehensions which have originated in the 
abundance and the difficulties attached to the subjects we 
would embrace, recede from view as we remember that with 
the increase of observations in the present day there has also 
arisen a more intimate knowledge of the connection existing 
among all phenomena. It has not unfrequently happened, 
that the researches made at remote distances have often and 
unexpectedly thrown light upon subjects which had long re- 
sisted the attempts made to explain them within the narrow 
limits of our own sphere of observation. Organic forms tliat 
had long remained isolated, both in the animal and vegetable 
kingdom, have been connected by the discovery of intermediate 
links or stages of transition. The geography of beings endov/ 



INTRODUCTION. 51 

ed with life attains completeness as we see the species, genera, 
and entire families belonging to one hemisphere, reflected, as 
it were, in analogous animal and vegetable forms in the oppo- 
site liemisphere. These are, so to speak, the equivalents w^hich 
mutually personate and replace one another in the great series 
of organisms. These connecting links and stages of transition 
may be traced, alternately, in a deficiency or an excess of de- 
velopment of certain parts, in the mode of junction of distinct 
organs, in the differences in the balance of forces, or in a re- 
semblance to intermediate forms which are not permanent, 
but merely characteristic of certain phases of normal devel- 
opment. Passing from the consideration of beings endowed 
with life to that of inorganic bodies, we find many striking 
illustrations of the high state of advancement to which modern 
geology has attained. We thus see, according to the grand 
views of Elie de Beaumont, how chains of mountains dividing 
different climates and floras and different races of men, reveal 
to us their relative age, both by the character of the sediment- 
ary strata they have uplifted, and by the directions which 
they follow over the long fissures with which the earth's crust 
is furrowed. Relations of superposition of trachyte and of 
syenitic porphyry, of diorite and of serpentine, which remuin 
doubtful when considered in the auriferous soil of Hungary, 
in the rich platinum districts of the Oural, and on the south- 
western declivity of the Siberian Altai, are elucidated by the 
observations that have been made on the plateaux of Mexico 
and Antioquia, and in the unhealthy ravines of Choco. The 
most important facts on which the physical history of the 
world has been based in modern times, have not been accu- 
mulated by chance. It has at length been fully acknowledg- 
ed, and the conviction is characteristic of the age, that the 
narratives of distant travels, too long occupied in the mere 
recital of hazardous adventures, can only be made a source of 
instruction where the traveler is acquainted with the condi- 
tion of the science he would enlarge, and is guided by reason 
in his researches. 

It is by this tendency to generalization, which is only dan- 
gerous in its abuse, that a great portion of the physical knowl- 
edge already acquired may be made the common property of 
all classes of society ; but, in order to render the instruction 
imparted by these means commensurate with the importance 
of the subject, it is desirable to deviate as widely as possible 
from the imperfect compilations designated, till the close of 
the eighteenth century, by t^e inappropriate term of popula? 



52 cosjMos. 

knowledge. I take pleasure in persuading myself that scien- 
tific subjects may be treated of in language at once dignified, 
grave, and animated, and that those who are restricted with- 
in the circumscribed limits of ordinary life, and have long re- 
mained strangers to an intimate communion with nature, 
may thus have opened to them one of the richest sources of 
enjoyment, by which the mind is invigorated by the acquisi- 
tion of new ideas. Communion with nature awakens within 
us perceptive faculties that bad long lain dormant ; and we 
thus comprehend at a single glance the influence exercised by 
physical discoveries on the enlargement of the sphere of intel- 
lect, and perceive how a judicious application of mechanics, 
chemistry, and other sciences may be made conducive to na- 
tional prosperity. 

A more accurate knowledge of the connection of physical 
phenomena will also tend to remove the prevalent error that 
all branches of natural science are not equally important in 
relation to general cultivation and industrial progress. An 
arbitrary distinction is frequently made between the various 
degrees of importance appertaining to mathematical sciences, 
to the study of organized beings, the knowledge of electro-" 
magnetism, and investigations of the general properties of mat- 
ter in its different conditions of molecular aggregation ; and it 
is not uncommon presumptuously to affix a supposed stigma 
upon researches of this nature, by terming them " purely the- 
oretical," forgetting, although the fact has been long attested, 
that in the observation of a phenomenon, which at first sight 
appears to be wholly isolated, may be concealed the germ of a 
great discovery. When Aloysio Galvani first stimulated the 
nervous fiber by the accidental contact of two heterogeneous 
metals, his cotemporaries could never have anticipated that 
the action of the voltaic pile would discover to us, in the al- 
kalies, metals of a silvery luster, so light as to swim on wa- 
ter, and eminently inflammable ; or that it would become a 
powerful instrument of chemical analysis, and at the same 
time a thermoscope and a magnet. When Huygens first ob- 
served, in 1678, the phenomenon of the polarization of light, 
exhibited in the difference between the two rays into which 
a pencil of light divides itself in passing through a doubly 
refracting crystal, it could not have been foreseen that, a 
century and a half later, the great philosopher Arago would, 
by his discovery of chromatic ijolarization, be led to discern, 
by means of a small fragment of Iceland spar, whether solar 
light emanates from a solid body or a gaseous covering, oi 



INTRODUCTION. 53 

whether comets transmit light directly or merely by reflec- 
tion.* 

An equal appreciation of all branches of the mathematical^ 
physical, and natural sciences is a special requirement of the 
present age, in which the material wealth and the growing 
prosperity of nations are principally based upon a more en- 
lightened employment of the products and forces of nature. 
The most superficial glance at the present condition of Europe 
shows that a diminution, or even a total annihilation of na- 
tional prosperity, must be the award of those states who shrink 
with slothful indifierence from the great struggle of rival na- 
tions in the career of the industrial arts. It is with nations 
as with nature, which, according to a happy expression of 
G6the,t " knows no pause in progress and development, and 
attaches her curse on all inaction." The propagation of an 
earnest and sound knowledge of science can therefore alone 
avert the dangers of which I have spoken. Man can not act 
upon nature, or appropriate her forces to his own use, without 
comprehending their full extent, and having an intimate ac- 
quaintance with the laws of the physical world. Bacon has 
said that, in human societies, knowledge is power. Both must 
rise and sink together. But the knowledge that results from 
the free action of thought is at once the delight and the in- 
destructible prerogative of man ; and in forming part of the 
wealth of mankind, it not unfrequently serves as a substitute 
for the natural riches, which are but spariiigly scattered over 
the earth. Those states which take no active part in the 
general industrial movement, in the choice and preparation of 
natural substances, or in the application of mechanics and 
chemistry, and among whom this activity is not appreciated 
by all classes of society, will infallibly see their prosperity di- 
minish in proportion as neighboring countries become strength- 
ened and invigorated under the genial influence of arts and 
sciences. 

As in nobler spheres of thought and sentiment, in philosophy, 
poetry, and the fine arts, the object at which we aim ought to 
be an inwaid one — an ennoblement of the intellect — so ought 
we likevidse, in our pursuit of science, to strive after a knowl- 
edge of the laws and the principles of unity that pervade the 
vital forces of the universe ; and it is by such a course that 

* Ai'ago's Discoveries ia the year 1811. — Delambre's Histoire de 
V Ait., p. 652. (Passage already quoted.) 

t Gothe, ill Die AphoHsmen uber Naturwissenschaft. — Werke, bd. 1... 
B. 4 



54 COSMOS. 

physical studies may be made subservient to the progress of in- 
dustry, which is a conquest of mind over matter. By a hap- 
py connection of causes and effects, we often see the useful link- 
ed to the beautiful and the exalted. The improvement of agri- 
culture in the hands of freemen, and on properties of a mod- 
erate extent — the flourishing state of the mechanical arts freed 
from the trammels of municipal restrictions — the increased 
impetus imparted to commerce by the multiplied means of 
contact of nations v^^ith each other, are all brilliant results of 
the intellectual progress of mankind, and of the amelioration 
of political institutions, in which this progress is reflected. 
The picture presented by modern history ought to convince 
those who are tardy in awakening to the truth of the lesson 
it teaches. 

Nor let it be feared that the marked predilection for the 
study of nature, and for industrial progress, which is so char- 
acteristic of the present age, should necessarily have a tenden- 
cy to retard the noble exertions of the intellect in the domains 
of philosophy, classical history, and antiquity, or to deprive 
the arts by which life is embellished of the vivifying breath of 
imagination. Where all the germs of civilization are devel- 
oped beneath the ff^gis of free institutions and wise legislation, 
there is no cause for apprehending that any one branch of 
knowledge should be cultivated to the prejudice of others. 
All afford the state precious fruits, whether they yield nourish- 
ment to man and constitute his physical wealth, or whether, 
more permanent in their nature, they transmit in the works 
of mind the glory of nations to remotest posterity. The Spar- 
tans, notwithstanding their Doric austerity, prayed the gods 
to grant them " the beautiful with the good."* 

I will no longer dwell upon the considerations of the influ- 
ence exercised by the mathematical and physical sciences on 
all that appertains to the material wants of social life, for the 
vast extent of the course on which I am entering forbids me 
to insist further upon the utility of these applications. Ac- 
customed to distant excursions, I may, perhaps, have erred in 
describing the path before us as more smooth and pleasant 
than it really is, for such is wont to be the practice of those 
who delight in guiding others to the summits of lofty mount- 
ains : they praise the view even when great part of the dis- 
tant plains lie hidden by clouds, knowing that this half-trans- 
parent vapory vail imparts to the scene a certain charm from 

* Pseudo-Plato. — Alcib., xi., p. 184, ed. Steph. ; Plut., Instituta La- 
conica, p. 253, ed. Hutten. 



, j\TKoDi;( rrox. oa 

the power exercised by the imagination over the domani of the 
senses. In like manner, from the height occupied by the phys- 
ical history of the world, all parts of the horizon will not ap- 
pear equally clear and well defined. This indistinctness will 
not, however, be wholly owing to the present imperfect state 
of some of the sciences, but in part, likewise, to the unskill- 
fulness of the guide who has imprudently ventured to ascend 
these lofty summits. 

The object of this introductory notice is not, however, solely 
to draw attention to the importance and greatness of the phys- 
ical history of the universe, for in the present day these are too 
well understood to be contested, but likewise to prove how, 
without detriment to the stability of special studies, we may 
be enabled to generalize our ideas by concentrating them in 
one conmion focus, and thus arrive at a point of view from 
w^hich all the organisms and forces of nature may be seen as 
one Hving, active whole, animated by one sole impulse, " Na- 
ture," as Schelling remarks in his poetic discourse on art, "is 
not an inert mass ; and to him who can comprehend her vast 
sublimity, she reveals herself as the creative force of the uni- 
verse — before all time, eternal, ever active, she calls to life all 
things, whether perishable or imperishable." 

By uniting, under one point of view, both the phenomena 
of our own globe and those presented in the regions of space, 
we embrace the limits of the science of the Cosmos, and con- 
vert the physical history of the globe into the physical history 
of the universe, the one term being modeled upon that of the 
other. This science of the Cosmos is not, however, to be re- 
garded as a. mere encyclopedic aggregation of the most im- 
portant and general results that have been collected together 
from special branches of knowledge. These results are noth- 
ing more than the materials for a vast edifice, and their com- 
bination can not constitute the physical history of the w^orld, 
whose exalted part it is to show the simultaneous action and 
the connecting links of the forces which pervade the universe. 
The distribution of organic types in different climates and at 
different elevations — that is to say, the geography of plants 
and animals — differs as widely from botany and descriptive 
zoology as geology does from mineralogy, properly so called. 
The physical history of the universe must not, therefore, be 
confounded with the Encyclopedias of the Natural Sciences, 
as they have hitherto been compiled, and whose title is as 
vao-ue as their limits are ill defined. In the work before us, 
partial facts will be considered only in relation to the whole 



5(j COSMOS. 

The higher the point of view, the greater is the nece*,sity lor 
a systematic mode of treating the subject in language at once 
animated and picturesque. 

But thought and language have ever been most intimately 
allied. If langiiage, by its originality of structure and its 
native richness, can, in its delineations, interpret thought M^ith 
grace and clearness, and if, by its happy flexibility, it can paint 
with vivid truthfulness the objects of the external world, it 
reacts at the same time upon thought, and animates it, as it 
were, with the breath of life. It is this mutual reaction which 
makes words more than mere signs and forms of thought ; and 
the beneficent influence of a language is most strikingly man- 
ifested on its native soil, where it has sprung spontaneously 
from the minds of the people, whose character it embodies. 
Proud of a country that seeks to concentrate her strength in 
intellectual unity, the writer recalls with delight the advant- 
ages he has enjoyed in being permitted to express his thoughts 
in his native language ; and truly happy is he who, in at- 
tempting to give a lucid exposition of the great phenomena of 
the universe, is able to draw from the depths of a language, 
which, through the free exercise of thought, and by the efiii- 
sions of creative fancy, has for centuries past exercised so pow- 
erful an influence over the destinies of man. 



M.MITS AND METHOD OF EXPOSITION OF THE PHYSICAL DESCRIPTION 

OF THE UNIVERSE. 

I HAVE endeavored, in the preceding part of my work, to 
explain and illustrate, by various examples, how the enjoy- 
ments presented by the aspect of nature, varying as they do 
in the sources from whence they flow, may be multiplied and 
ennobled by an acquaintance with the connection of phenom- 
ena and the laws by which they are regulated. It remains, 
then, for me to examine the spirit of the method in which the 
exposition of the physical descriiJtion of the utiiverse should 
be conducted, and to indicate the limits of this science in ac- 
cordance with the views I have acquired in the course of my 
studies and travels in various parts of the earth. I trust I 
may flatter myself with a hope that a treatise of this nature 
will justify the title I have ventured to adopt for my work, 
and exonerate me from the reproach of a presumption that 
would be doubly reprehensible in a scientific discussion. 

Before entering upon the delineation of the partial phenom- 



INTRODUCTION. 57 

ena which are found to be distributed in various g^roups, I would 
consider a few general questions intimately connected together, 
and bearing upon the nature of our kno^vledge of the external 
world and its different relations, in all epochs of history and in 
all phases of intellectual advancement. Under this head will 
be comprised the following considerations : 

1 . The precise limits of the physical description of the uni- 
verse, considered as a distinct science. 

2. A brief enumeration of the totality of natural phenomena, 
presented under the form of a general delineatioii of nature. 

3. The influence of the external world on the imagination 
and feelings, which has acted in modern times as a powerful 
impulse toward the study of natural science, by giving anima- 
tion to the description of distant regions and to the delineation 
of natural scenery, as far as it is characterized by vegetable 
physiognomy and by the cultivation of exotic plants, and their 
arrangement in well- contrasted groups. 

4. The history of the contemplation of nature, or the pro- 
gressive development of the idea of the Cosmos, considered 
with reference to the historical and geographical facts that 
have led to the discovery of the connection of phenomena. 

The higher the point of view from which natural phenome- 
na may be considered, the more necessary it is to circumscribe 
the science within its just limits, and to distinguish it from all 
other analogous or auxiliary studies. 

Physical cosmography is founded on the contemplation of all 
created things-:-all that exists in space, whether as substances 
or forces — that is, all the material beings that constitute the 
universe. The science which I would attempt to define pre- 
sents itself, therefore, to man, as the inhabitant of the earth, 
under a two-fold form — as the earth itself and the reo-ions of 
space. It is with a view of showing the actual character and 
the independence of the study of physical cosmography, and at 
the saraie time indicating the nature of its relations to general 
fhysics, descrij)tive natural history, geology, and comparative 
geography, that I will pause for a few moments to consider 
that portion of the science of the Cosmos which concerns the 
earth. As the history of philosophy does not consist of a mere 
material enumeration of the philosophical views entertained 
in different ages, neither should the physical description of the 
universe be a simple encyclopedic compilation of the sciences 
we have enumerated. The difficulty of defining the limits of 
intimately-connected studies has been increased, because for 
centuries it has been customary to designate various branches 

C2 



58 COSMOS. 

of empirical knowledge by terms which admit either ot too 
wide or too limited a definition of the ideas which they were 
intended to convey, and arc, besides, objectionable from hav- 
ing had a different signification in those classical languages of 
antiquity from which they have been borrowed. The terms 
physiology, physics, natural history, geology, and geography 
arose, and were commonly used, long before clear ideas were 
entertained of the diversity of objects embraced by these 
sciences, and consequently of their reciprocal limitation. Such 
is the influence of long habit upon language, that by one of 
the nations of Europe most advanced in civilization the word 
" physic" is applied to medicine, while in a society of justly 
deserved universal reputation, technical chemistry, geology, 
and astronomy (purely experimental sciences) are comprised 
under the head of" Philosophical Transactions." 

An attempt has often been made, and almost always in vain, 
to substitute new and more appropriate terms for these ancient 
designations, which, notwithstanding their undoubted vague- 
ness, are now generally understood. These changes have been 
proposed, for the most part, by those who have occupied them- 
selves with the general classification of the various branches 
of knowledge, from the first appearance of the great encyclo- 
pedia [Margarita Pliilosophica) of Gregory Reisch,* prior of 
the Chartreuse at Freiburg, toward the close of the fifteenth 
century, to Lord Bacon, and from Bacon to D'Alembert ; and 
in recent times to an eminent physicist, Andre Marie Ampere. t 

* The Margarita PhilosopJiica of Gregory Reisch, prior of the Char- 
treuse at Freiburg, first appeared under the following title : Epitome 
omnis Philosophice, alias Margarita PhilosopJiica, tractans de omni generi 
scibili. The Heidelberg edition (1486), and that of Strasburg (1504), 
both bear this title, but the first part was suppi'essed in the Freiburg 
edition of the same year, as well as in the twelve subsequent editions, 
vvhich succeeded one another, at short intervals, till 1.535. This work 
exercised a great influence on the ditfusion of mathematical and physic- 
al sciences toward the beginning of the sixteenth century, and CLas^es, 
the learned author of L'Apercu Historique des Methodes en GeomHrtc 
(1837), has shown the great importance of Reisch's Encyclopedia in 
the history of mathematics in the Middle Ages. I have had recourse 
to a passage in the Margarita PhilosopTiica, found only in the edition 
of 1513, to elucidate the important question of the relations between 
the statements of the geographer of Saint-Die, Hylacomilus (Martin 
VValdseemiiller), the first who gave the name of America to the New 
Continent, and those of Amerigo Vespucci, Rene, King of Jerusalem 
and Duke of Lorraine, as also those contained in the celebrated editions 
of Ptolemy of 1513 and 1522. See my Examen Critique de la G^o- 
grapkip. du Nouveau Continent, et des Progres de V Astronomie Nautiqtie 
aux 15e et 16e Siecles, t. iv., p. 99-125. 

t Ampere, Essai sn.r la Phil, des Sciences, 1834, p. 25. Whewell, 



IXTHODITTroW 59 

The selection of an inappropriate Greek nomenclature has per- 
haps been even more prejudicial to the last of these attempts 
than the injudicious use of binary divisions and the excessive 
multiplication of groups. 

The physical description of the world, considering the uni- 
verse as an object of the external senses, does undoubtedly re- 
quire the aid of general physics and of descriptive natural histo- 
ly, but the contemplation of all created thmgs, which are hnked 
together, and form one luhole, animated by internal forces, gives 
to the science we are considering a peculiar character. Phys- 
ical science considers only the general properties of bodies ; it 
is the product of abstraction — a generalization of perceptible 
phenomena ; and even in the work in which were laid the 
first foundations of general physics, in the eight books on 
physics of Aristotle,* all the phenomena of nature are consid- 
ered as depending upon the primitive and vital action of one 
sole force, from which emanate all the movements of the uni- 
verse. The terrestrial portion of physical cosmography, for 
which I would willingly retain the expressive designation of 
'physical geograjjhij, treats of the distribution of magnetism in 
our planet with relation to its intensity and direction, but does 
not enter into a consideration of the laws of attraction or re- 
pulsion of the poles, or the means of eliciting either permanent 
or transitory electro-magnetic currents. Physical geography 
depicts in broad outlines the even or irregular configuration of 
continents, the relations of superficial area, and the distribution 
of continental masses in the two hemispheres, a distribution 
which exercises a powerful influence on the diversity of climate 
and the meteorological modifications of the atmosphere ; this 
science defines the character of mountain chains, which, hav- 
ing been elevated at different epochs, constitute distinct sys- 
tems, whether they run in parallel lines or intersect one an- 
other ; determines the mean height of continents above the 
level of the sea, the position of the center of gravity of their 
volume, and the relation of the highest summits of mountain 
chains to the mean elevation of their crests, or to their prox- 
imity with the sea-shore. It depicts the eruptive rocks as 
principles of movement, acting upon the sedimentary rocks by 
traversing, uplifting, and inchning them at various angles ; it 

Philosophy of the Inductive Sciences, volt ii., p. 277. Park, Pantoiogy^ 

* All changes in the physical world may be reduced to motion. 
Aristot., Phys. Ansc, iii., 1 and 4, p. 200, 201. Bekker, viii., 1, 8, and 
9, p. 250, 262, 265. De Genere et Corr., ii., 10, p. 336. Psendo-Aris- 
tot., De Mundo. cap. vi., p. 398. 



.«|HX^ 



60 COSMOS. 

considers volcanoes either as isolated, or ranged in single or in 
double series, and extending their sphere of action to various 
distances, either by raising long and narrow lines of rocks, or 
by means of circles of commotion, which expand or diminish 
in diameter in the course of ages. This terrestrial portion ot 
the science of the Cosmos describes the strife of the liquid ele- 
ment with the solid land ; it indicates the features possessed 
in common by all great rivers in the upper and lower portion 
of their course, and in their mode of bifurcation when their 
basins are unclosed ; and shows us rivers breaking through 
the highest mountain chains, or following for a long time a 
course parallel to them, either at their base, or at a consider- 
able distance, Avhere the elevation of the strata of the mount- 
ain system and the direction of their inclination correspond 
to the configuration of the table-land. It is only the general 
results of comparative orography and hydrography that belong 
to the science whose true limits I am desirous of determining, 
and not the special enumeration of the greatest elevations of 
our globe, of active volcanoes, of rivers, and the number of 
their tributaries, these details falling rather within the domain 
of geography, properly so called. We would here only con- 
sider phenomena in their mutual connection, and in their re- 
lations to different zones of our planet, and to its physical con- 
stitution generally. The specialities both of inorganic and or- 
ganized matter, classed according to analogy of form and com- 
position, undoubtedly constitute a most interesting branch of 
study, but they appertain to a sphere of ideas having no affin- 
ity with the subject of this work. 

The description of different countries certainly furnishes us 
with the most important materials for the composition of a 
physical geography ; but the combination of these differenl 
descriptions, ranged in series, would as little give us a tru« 
image of the general conformation of the irregular surface of 
our globe, as a succession of all the floras of different region? 
would constitute that M^iich I designate as a Geogra2)hy of 
Plants. It is by subjecting isolated observations to the process 
of thought, and by combining and comparing them, that we 
are enabled to discover the relations existing in common be 
tween the climatic distribution of beings and the individualitj 
of organic forms (in the morphology or descriptive natural his- 
tory of plants and animals) ; and it is by induction that we 
are led to comprehend numerical laws, the proportion of nat- 
ural families to the whole number of species, and to desig-nate 
the latitude or geographical position of the zones in whose 



INTRODUCTION. 61 

plains each org:anic form attains the maximum of its develop- 
ment. Considerations of this nature, by their tendency to 
generalization, impress a nobler character on the physical de- 
scription of the globe, and enable us to undfrstand how the 
aspect of the scenery, that is to say, the impression produced 
upon the mind by the physiognomy of the vegetation, depends 
upon the local distribution, the number, and the luxuriance of 
growth of the vegetable forms predominating in the general 
mass. The catalogues of organized beings, to which was for- 
merly given the pompous title of Systems of Nature, present 
us with an admirably connected arrangement by analogies of 
structure, either in the perfected development of these beings, 
or in the different phases which, in accordance with the views 
of a spiral evolution, affect in vegetables the leaves, bracts, 
calyx, corolla, and fructifying organs ; and in animals, with 
more or less symmetrical regularity, the cellular and fibrous 
tissues, and their perfect or but obscurely developed articula- 
tions. But these pretended systems of nature, however ingen- 
ious their mode of classification may be, do not show us or- 
ganic beings as they are distributed in groups throughout our 
planet, according to their difierent relations of latitude and 
elevation above the level of the sea, and to climatic influences, 
which are owing to general and often very remote causes. 
The ultimate aim of physical geography is, however, as we 
have already said, to recognize unity in the vast diversity of 
phenomena, and by the exercise of thought and the combina- 
tion of observations, to discern the constancy of phenomena 
in the midst of apparent changes. In the exposition of the 
terrestrial portion of the Cosmos, it will occasionally be neces- 
sary to descend to veiy special facts ; but this will only be in 
order to recall the connection existing betM^een the actual dis- 
tribution of organic beings over the globe, and the laws of the 
ideal classification by natural families, analogy of internal or- 
ganization, and progressive evolution. 

It follows from these discussions on the limits of the various 
sciences, and more particularly from the distinction which must 
necessarily be made between descriptive botany (morphology 
of vegetables) and the geography of plants, that in the phys 
ical history of the globe, the innumerable multitude of organ- 
ized bodies which embellish creation are considered rather ac- 
cording to zones of habitation or stations, and to differently 
inflected isothermal bands, than with reference to the princi- 
ples of gradation in the development of internal organism. 
Notwithstanding this, botany and zoology, which constitute 



62 COSMOS. 

the descriptive natural history of all organized beings, are the 
fruitful sources whence we draw the materials necessary to 
give a solid basis to the study of the mutual relations and 
connection of phenomena. 

We will here subjoin one important observation by way of 
elucidating the connection of which we have spoken. The 
first general glance over the vegetation of a vast extent of a 
continent shows us forms the most dissimilar — Graminese and 
Orchideee, Coniferse and oaks, in local approximation to one 
another ; while natural families and genera, instead of being 
locally associated, are dispersed as if by chance. This disper- 
sion is, however, only apparent. The physical description of 
the globe teaches us that vegetation every where presents nu- 
merically constant relations in the development of its forms 
and types ; that in the same climates, the species which are 
wanting in one country are replaced in a neighboring one by 
other species of the same family ; and that this laiv of substi- 
tution, which seems to depend upon some inherent mysteries 
of the organism, considered with reference to its origin, main- 
tains in contiguous regions a numerical relation between the 
species of various great families and the general mass of the 
phanerogamic plants constituting the two floras. We thus 
find a principle of unity and a primitive plan of distribution 
revealed in the multiplicity of the distinct organizations by 
which these regions are occupied ; and we also discover in 
each zone, and diversified according to the families of plants, 
a slow but continuous action on the aerial ocean, depending 
upon the influence of light — the primary condition of all or- 
ganic vitality — on the solid and liquid surface of our planet. 
It might be said, in accordance with a beautiful expression of 
Lavoisier, that the ancient marvel of the myth of Prometheus 
was incessantly renewed before our eyes. 

If we extend the course which we have proposed, following 
in the exposition of the physical description of the earth to the 
sidereal part of the science of the Cosmos, the delineation of 
the regions of space and the bodies by which they are occupied, 
we shall find our task simplified in no common degree. If, ac- 
cording to ancient but unphilosophical forms of nomenclature, 
we would distinguish between physics, that is to say, general 
considerations on the essence of matter, and the forces by which 
it is actuated, and chemistry, which treats of the nature of 
substances, their elementary composition, and those attrac- 
tions that are not determined solely by the relations of mass, 
we must admit that the description of the earth comprises at 



INTRODUCTION. (53 

once physical and chejiiical actions. In addition to gravita- 
tion, which must be considered as a primitive force in nature, 
we observe that attractions of another kind are at work around 
us, both in the interior of our planet and on its surface. These 
forces, to which we apply the term chemical ajjinity, act upon 
molecules in contact, or at infinitely minute distances from one 
another,* and which, being differently modified by electricity, 
heat, condensation in porous bodies, or by the contact of an 
intermediate substance, animate equally the inorganic world 
and animal and vegetable tissues. If we except the small 
asteroids, which appear to us under the forms of aerolites and 
shooting stars, the regions of space have hitherto presented to 
our direct observation physical phenomena alone ; and in the 
case of these, we know only with certainty the effects depend- 
ing upon the quantitative relations of matter or the distribu- 
tion of masses. The phenomena of the regions of space may 
consequently be considered as influenced by simple dynamical 
laws — the laws of motion. 

The effects that may arise from the specific difference and 
the heteroofeneous nature of matter have not hitherto entered 
into our calculations of the mechanism of the heavens. The 
only means by which the inhabitants of our planet can enter 
into relation with the matter contained within the regions of 
space, whether existing in scattered forms or united into large 
spheroids, is by the phenomena of light, the propagation of 
luminous waves, and by the influence universally exercised by 
the force of gravitation or the attraction of masses. The ex- 
istence of a periodical action of the sun and moon on the va- 
riations of terrestrial magnetism is even at the present day 
extremely problematical. We have no direct experimental 
knowdedge regarding the properties and specific qualities of 
the masses circulating in space, or of the matter of w^hich they 
are probably composed, if we except what may be derived from 
the fall of aerolites or meteoric stones, wdiich, as we have al- 
ready observed, enter within the limits of our terrestrial sphere. 
It will be sufficient here to remark, that the direction and the 
excessive velocity of projection (a velocity wholly planetary) 
manifested by these masses, render it more than probable that 

* On the question already discussed by Newton, regarding the differ- 
ence existing between the atti-action of masses and molecular attraction, 
see Laplace, Exposition du Systeme du Monde, p. 384, and supplement 
to book X. of the Mecanique Celeste, p, 3, 4 ; Kant, Metaph. AnfangR. 
grunde der Naturwissenschaft, Sam. Werke, 1839, bd. v., s. 309 (Meta- 
physical Principles of the Natural Sciences) ; Pectet, Physique, 1838- 
vol, i., p. 59-63. 



64 COSMOS. 

they are small celestial bodies, which, being attracted by out 
planet, are made to deviate from their original course, and thus 
reach the earth enveloped in vapors, and in a high state of 
actual incandescence. The familiar aspect of these asteroids, 
and the analogies which they present with the minerals com- 
posing the earth's crust, undoubtedly afford ample grounds for 
surprise ;* but, in my opinion, the only conclusion to be drawn 
from these facts is, that, in general, planets and other sidereal 
masses, which, by the influence of a central body, have been 
agglomerated into rings of vapor, and subsequently into sphe- 
roids, being integrant parts of the same system, and having 
one common origin, may likewise be composed of substances 
chemically identical. Again, experiments with the pendulum, 
particularly those prosecuted with such rare precision by Bes- 
sel, confirm the Newtonian axiom, that bodies the most hete- 
rogeneous in their nature (as water, gold, quartz, granular 
limestone, and diflerent masses of aerolites) experience a per- 
fectly similar degree of acceleration from the attraction of the 
earth. To the experiments of the pendulum may be added 
the proofs furnished by purely astronomical observations. The 
almost perfect identity of the mass of Jupiter, deduced from the 
influence exercised by this stupendous planet on its own satel- 
lites, on Encke's comet of short period, and on the small planets 
Vesta, Juno, Ceres, and Pallas, indicates with equal certain- 
ty that within the limits of actual observation attraction is 
determined solely by the quantity of matter. t 

This absence of any perceptible difierence in the nature of 
matter, alike proved by direct observation and theoretical de- 
ductions, imparts a high degree of simplicity to the mechanism 
of the heavens. The immeasurable extent of the regions of 
space being subjected to laws of motion alone, the sidereal 
portion of the science of the Cosmos is based on the pure and 
abundant source of mathematical astronomy, as is the terres- 
trial portion on physics, chemistry, and organic morphology ; 
but the domain of these three last-named sciences embraces 

* [The analysis of an aeroHte which fell a few years since in Mary 
land. United States, and was examined by Professor Silliman, of New 
Haven, Connecticut, gave the following results: Oxyd of iron, 24 ; ox- 
yd of nickel, 1*25 ; silica, with earthy matter, 3*46 ; sulphur, a trace 
=28-71. Dr. Mantell's Wonders of Geology, 1848, vol. i.. p. 51.]— 7V. 

t Poisson, Connaissances des Temps pour V Annee 1836, p. (j4-6(). 
Bessel, Poggeudorf 's Annalen, bd. xxv., s. 417. Encke, Abhandhingen 
der Berliner Academie (Trans, of the Berlin Academy), 1826, s. 257. 
Mitscherlich, Lehrbuck der Chemie (Manual of Chemistry), 1837 bd. i. 
8. 352. 



INTRODUCTION. 65 

the consideration of phenomena which are so complicated, 
and have, up to the present time, been found so little suscep- 
tible of the application of rigorous method, that tht) physical 
science of the earth can not boast of the same certainty and 
simplicity in the exposition of facts and their mutual connec- 
tion which characterize the celestial portion of the Cosmos. 
It is not improbable that the difference to which we allude 
may furnish an explanation of the cause which, in the earliest 
ages of intellectual culture among the Greeks, directed the 
natural philosophy of the Pythagoreans with more ardor to the 
heavenly bodies and the regions of space than to the earth 
and its productions, and how through Philolaiis, and subse- 
quently through the analogous views of Aristarchus of Samos, 
and of Seleucus of Erythrea, this science has been made more 
conducive to the attainment of a knowledge of the true system 
of the world than the natural philosophy of the Ionian school 
could ever be to the physical history of the earth. Giving but 
little attention to the properties and specific differences of 
matter filling space, the great Italian school, in its Doric 
gravity, turned by preference toward all that relates to meas- 
ure, to the form of bodies, and to the number and distances of 
the planets,*" while the Ionian physicists directed their atten 
tion to the qualities of matter, its true or supposed metamor 
phoses, and to relations of origin. It was reserved for the 
powerful genius of Aristotle, alike profoundly speculative and 
practical, to sound with equal success the depths of abstraction 
and the inexhaustible resources of vital activity pervading the 
material world. 

Several highly distinguished treatises on physical geography 
are prefaced by an introduction, whose purely astronomical 
sections are directed to the consideration of the earth in its 
planetary dependence, and as constituting a part of that great 
system which is animated by one central body, the sun. This 
course is diametrically opposed to the one which I propose 
following. In order adequately to estimate the dignity of the 
Cosmos, it is requisite that the sidereal portion, termed by 
Kant the oiaturaL history of the heavens, should not be made 
subordinate to the terrestrial. In the science of the Cosmos, 
according to the expression of Aristarchus of Samos, the pio- 
neer cf •the Copernican system, the sun, with its satellites, 
was nothing more than one of the innumerable stars by which 
space is occupied. The physical history of the world must, 
therefore, begin with the description of the heavenly bodies, 
* Compare Otfried MUller's Dorien, bd. i., s. 365. 



■U6 ^ COSMOS. 

and with a geographical sketch of the universe, or, I would 
rather say, a true map of the ivorld, such as was traced by 
the bold hand of the elder Herschel. If, notwithstanding the 
sraallness of our planet, the most considerable space and the 
most attentive consideration be here afforded to that which 
exclusively concerns it, this arises solely from the disproportion 
in the extent of our knowledge of that which is accessible and 
of that which is closed to our observation. This subordina- 
tion of the celestial to the terrestrial portion is met with in the 
great work of Bernard Varenius,'* w^hich appeared in the mid- 

* Geographia Generalis iii qua affectiones generales telluris expli- 
cantur. The oldest Elzevir edition bears date 1650, the second 1672, 
and the third 1681 ; these were published at Cambridge, under New- 
ton's supervision. This excellent work by Varenius is, in the true 
sense of the words, a physical description of the earth. Since the work 
Hlstoria Natural de las Indias, 1590, in which the Jesuit Joseph de 
Acosta sketched in so masterly a manner the delineation of the New 
Continent, questions relating to the physical history of the earth have 
never been considered with such admirable generality. Acosta is rich- 
er in original observations, while Varenius embraces a wider circle of 
ideas, since his sojourn in Holland, which was at that period the center 
of vast commercial relations, had brought him in contact with a great 
number of w^ell-informed travelers. Generalis sive Universalis Geo- 
graphia dicitJir qute tellurem in genere considerat atque affectiones ex' 
plicat, non^ habita particulariitm regionum ratione. The general de- 
scription of the earth by Varenius {Pars Ahsoluta, cap. i.-xxii.) maybe 
considered as a treatise of comparative geography, if we adopt the term 
used by the author h.\m?,e\i {Geographia Comparativa, cap.xxxiii.-xl.), 
although this must be understood in a limited acceptation. We may 
cite the following among the most remarkable passages of this book : 
the enumeration of the systems of mountains ; the examination of the 
relations existing between their directions and the general form of con- 
tinents (p. 66, 76, ed. Cantab., 1681); a list of extinct volcanoes, and 
such as were still in a state of activity ; the discussion of facts relative 
to the general distribution of islands and archipelagoes (p. 220) ; the 
depth of the ocean I'elatively to the height of neighboring coasts (p. 103) ; 
the uniformity of level observed in all open seas (p. 97) ; the depend- 
ence of currents on the prevailing winds; the unequal saltness of the 
sea; the configuration of shores (p. 139); the direction of the winds as 
the result of ditferences of temperature, &c. We may further instance 
the remarkable considerations of Varenius regarding the equinoctial 
current from east to west, to which he attributes the origin of the Gulf 
Stream, beginning at Cape St. Augustiu, and issuing forth between 
Cuba and Florida (p. 140). Nothing can be more accurate than his 
description of the current which skirts the western coast of Africa, be- 
tween Cape Verde and the island of Fernando Po in the Gulf of Guinea. 
Varenius explains the formation of sporadic islands by supposing them 
to be *' the raised bottom of the sea:" magna spirihium inclusorum vi, 
sicut aliquando monies e terra protttsos esse quidam scribunt (p. 225). 
The edition published by Newton in 1681 {auciior et emendatior) un^ 
fortunately contains no additions from this great authority; and there 
is not even mention made of the polar compression of the globe, al- 



IXTIIODUCTIOX. 07 

d\e of the seventeenth century. He was tlie first to distinguish 
between general a?id special geography, the former of which 
he subdivides into an absolute, or, properly speaking, terres- 
trial part, and a relative or planetary portion, according to 
the mode of considering our planet either with reference to its 
surface in its diliereiit zones, or to its relations to the sun and 
moon. It redounds to the glory of Varenius that his work on 
General and Comparative Geography should in so high a 
degree have arrested the attention, of Newton. The imper- 
fect state of many of the auxiliary sciences from which this 
. writer was obliged to draw his materials prevented his work 
from corresponduig to the greatness of the design, and it was 
reserved for the present age, and for my own country, to see 
the delineation of comparative geography, drawn in its full 
extent, and in all its relations with the history of man, by the 
skillful hand of Carl Ritter.* 

The enumeration of the most important results of the as- 
tronomical and physical sciences which in the history of the 
Cosmos radiate toward one common focus, may perhaps, to a 
certain degree, justify the designation I have given to my 
work, and, considered within the circumscribed limits I have 
proposed to myself, the undertaking may be esteemed less ad- 
venturous than the title. The introduction of new terms, es- 
pecially with reference to the general results of a science which 

- though the experiments on the pendulum by Richer had been made 
nine years prior to the appearance of the Cambridge edition. Newton's 
Principia Mathematica Philosojjhice Natnralis were not communicated 
in manuscript to tlie Royal Society until April, 1G80. Much uncer- 
tainty seems to prevail regarding the birth-place of Varenius. Ja;cher 
says it was England, while, according to La Biographie Universclle 
(b. xlvii., p. 495), he is stated to have been bom at Amsterdam; but 
it would appear, from the dedicatory address to the burgomaster ol 
that city (see his Geographia Comparativa), that both suppositions ai'e 
false. Varenius expressly says that lie had sought refuge in Amsterdam, 
*' because his native city had been burned and completely destroyed 
during a long war," words which appear to apply to the north of Ger- 
many, and to the devastations of the Thirty Years' War. In his dedica- 
tion of another work, Descriptio regni Japonic^ (Amst., 1649), to the 
Senate of Hamburgh, Varenius says that he prosecuted his elementary 
mathematical studies in the gymnasium of that city. There is, there- 
fore, every reason to believe that this admirable geographer was a 
native of Germany, and was probajjly born at Luneburg ( TFV/^e?i. Mem. 
Theol., 1685, p. 2142; Zedler, Universal Lexicon, vol. xlvi., 1745. p. 
187). 

* Carl Ritter's Erdkundeim VerhuUniss zur Naturund zvr Geschichte 
des Menschen, oder allgemeine vergleichende Geographic (Geojjraphy in 
relation to Nature and the History o' Man, or general Comparativo 
Geography). 



68 COSMOS. 

ought to be accessible to all, has always been greatly in oppo- 
sition to my own practice ; and whenever I have enlarged 
upon the established nomenclature, it has only been in the 
specialities of descriptive botany and zoology, where the in- 
troduction of hitherto unknown objects rendered new names 
necessary. The denominations of physical descriptions of the 
universe, or physical cosmography, which I use indiscrimin- 
ately, have been modeled upon those o{ physical descriptio?is 
of the earth, that is to say, physical geography, terms that 
have lonor heen in common use. Descartes, whose o^enius was 
one of the most powerful manifested in any age, has left us a 
few fragments of a great work, which he intended publishing 
under the title of Monde, and for which he had prepared him- 
self by special studies, including even that of human anatomy. 
The uncommon, but definite expression of the science of the 
Cosmos recalls to the mind of the inhabitant of the earth that 
we are treating of a more wddely-extended horizon — of the 
assemblage of all things with which space is filled, from the 
remotest nebula? to the climatic distribution of those delicate 
tissues of vegetable matter which spread a variegated cover- 
ins: over the surface of our rocks. 

The influence of narrow-minded views peculiar to the ear- 
lier ages of civilization led in all languages to a confusion of 
ideas in the synonymic use of the words earth and tvorld, 
while the common expressions voyages round the ivorld, map 
of the ivorld, and neiu ivorld, afford further illustrations of the 
same confusion. The more noble and precisely-defined ex- 
pressions of system of the ivorld, the planetary ivorld, and 
creation and age of the ivorld, relate either to the totality of 
the substances by which space is filled, or to the origin of" the 
whole universe. 

It was natural that, in the midst of the extreme variability 
of phenomena presented by the surface of our globe, and the 
aerial ocean by which it is surrounded, man should have been 
impressed by the aspect of the vault of heaven, and the uni- 
form and regular movements of the sun and planets. Thus 
the word Cosmos, which primitively, in the Homeric ages, in- 
dicated an idea of order and harmony, was subsequently adopt- 
ed in scientific language, where it was gradually applied to 
the order observed in the movements of the heavenly bodies, 
to the whole universe, and then finally to the world in which 
this harmony was reflected to us. According to the assertion 
of Philolaiis, whose fragmentary works have been so ably com- 
mented upon by Bockh, and conformably to the general testi- 



INTRODUCTION. 69 

mony of antiquity, Pythagoras was the first who used the 
word Cosmos to designate the order that reigns in the uni- 
verse, or entire world.* 

* Koofioc, in the most ancient, and at the same time most precise, 
definition of the word, signified ornament (as an adornment for a man, 
a woman, or a horse) ; taken figuratively for evra^ia, it implied, the or- 
der or adornment of a discourse. According to the testimony of all the 
ancients, it was Pythagoras who first used the word to designate the 
order in the universe, and the universe itself. Pythagoras left no writ- 
ings ; but ancient attestation to the truth of this assertion is to be found 
in several passages of the fragmentary works of Philolatis (Stob., Eclog., 
p. 360 and 460, Heeren), p. 62, 90, in Bockh's German edition. I do 
not, according to the example of Niike, cite Tim.'eus of Locris, since hia 
authenticity is doubtful. Plutarch {De plac. Phil., ii., 1) says, in the 
most express manner, that Pythagoras gave the name of Cosmos to the 
universe on account of the order which reigned throughout it; so like- 
wise does Galen {Hist. Phil., p. 429). This word, together with its 
novel signification, passed from the schools of philosophy into the lan- 
guage ot poets and prose writers. Plato designates the heavenly bod- 
ies by the name of Uranos, but the order pervading the regions of space 
he too terms the Cosmos, and in his Timmus (p. 30, b.) he says that the 
world is an animal endowed tcith a soul {KOCfiov ^cjou kiiypv^ov). Com- 
pare Anaxag. Claz., ed. Schaubach, p. Ill, and Plut. {De plac. Phil., 
ii., 3), on spirit apart from matter, as the ordaining power of nature. 
In Aristotle {De Casio, 1, 9), Cosmos signifies " the universe and the 
order pervading it," but it is likewise considered as divided in space 
into two parts — the sublunary world, and the world above the moon. 
{Meteor., I., 2, 1, and I., 3, 13, p. 339, a, and 340, b, Bekk.) The def- 
inition of Cosmos, which I have already cited, is taken from Pseudo-Ar- 
istoteles de Mundo, cap. ii. (p. 391); tte passage referred to is as fol- 
lows: Koa^og earl nvoTijua kg ovpavov koL yfjg Kul tuv ev Tovrotg Trepte- 
XOfiivuif (pvaeov. AeyeTac de Kal eKepcog K6a2,og rj ribv bT^uv rd^ig re kuI 
6iaK6(yfj,r]aig, vno t^euv re Kai did d^aijv (pv/iaTTOfiivri. Most of the pas- 
sages occurring in Greek writers on the word Cosmos may be found 
collected together in the controversy between Richard Bentley and 
Charles Boyle {Opuscula Philologica, 1781, p. 347, 445; Dissertation 
iipon the Epistles of Phalaris, 1817, p. 254) ; on the histoiical existence 
of Zaleucus, legislator of Leucris, in Nake's excellent work, Sched. 
Crit., 1812, p. 9, 15; and, finally, in Thcophilus Schmidt, ad Cleom. 
Cycl. Theor., met. I., 1, p. ix., 1, and 99. Taken in a more limited 
sense, the word Cosmos is also used in the plural (Plut., 1, 5), either to 
designate the stars (Stob., 1, p. 514; Plut., 11, 13), or the innumerable 
systems scattered like Islands through the immensity of space, and each 
composed of a sun and a moon. (Anax. Claz., Fragm., p. 89, 93, 120; 
Brandis, Gesck. der Griechisck-Romischen Philosophie, h. i., s. 252 (His- 
tory of the Greco-Roman Philosophy). Each of these groups forming 
thus a Cosmos, the universe, to ttuv, the word must be understood in a 
wider sense (Pint., ii., 1). It was not until long after the time of the 
Ptolemies that the word was applied to the earth. Bockh has made 
known inscnptions in praise of Trajan and Adrian ( Corpus Inscr. Grcec., 
1, n. 334 and 1036), in which Koafiog occurs for oLKOVjiivrj, in the same 
manner as we still use the term world to signify the earth alone. We 
have already mentioned the singular division of the regions of space 



70 COSMOS. 

From the Italian school of philosophy, the expression pass- 
ed, in this signification, into the language of those early poets 

into three parts, the Olympus, Cosmos, and Oui\tnos (Stob., i., p. 488; 
Philolatis, p. 94, 202) ; this division applies to the dilTerent regions sur 
i-Qunding that mysterious focus of the universe, the 'Earia rov iravTot, 
of the Pythagoreans. In the fragmentary passage in which this divi- 
sion is found, the term Ouranos designates the innermost region, situ- 
ated between the moon and earth ; this is the domain of changing 
things. The middle region, where the planets circulate in an invaria- 
ble and harmonious order, is, in accordance with the special coucep- 
tions entertained of tlie universe, exclusively termed Cosmos, while the 
word Olympus is used to express the exterior or igneous region. 13opp, 
the profound philologist, has remarked, that we may deduce, as Pott 
has done, Etymol. Forschungeii, th. i., s. 39 and 252 {Eiymol. Research- 
es), the word Koa^og from the Sanscrit root 'sud\ purificari, by assum- 
ing two conditions; first, that the Greek k in koo^oq comes from the 
palatial c, which Bopp represents by 's and Pott by c (in the same man- 
ner as diKa, decern, taih^m in Gothic, comes from the Indian word del- 
ean), and, next, that the Indian d' corresponds, as a general rule, with 
the Greek 6 ( Vergleichende Grammatik, $ 99 — Comparative Grammar), 
which shows the relation of Koa/xoc (for Kodfxog) with the Sanscrit root 
^sud\ whence is also derived Kada^ibg. Another Indian term for the 
world is gagat (pronounced dschagat), which is, properly speaking, the 
present participle of the verb gagdmi (I go), the root of which is gd. 
In restricting ourselves to the circle of Hellenic etymologies, we find 
{Etymol. M., p. 532, 12) that Koojiog is intimately associated with wafw, 
or rather with Kacvvfiac, whence we have KeKaafievog or KCKac^fxEvog. 
Welcker (Eine Kretische Col. in Thebcn, s. 23 — A Cretan Colony in 
Thebes) combines with this the name Kadjiog, as in Hesychius Kud/nog 
signifies a Cretan suit of anus. When the scientific language of Greece 
w^as introduced among the Romans, the word mundus, which at first had 
only the primary meaning of /cda/^of (female ornament), was applied to 
designate the entire universe. Ennius seems to have been the first 
who ventui-ed upon this innovation. In one of the fragments of this 
poet, preserved by Macrobius, on the occasion of his quarrel with Vir- 
gil, we fiud the word used in its novel mode of acceptation : " Micitdus 
coeli vastus constitit silentio''^ (Sat., vi., 2). Cicero also says, ^'Qvem nos 
lucentem mundum vocamus^^ (Timajus, S. de Univer., cap. x.). The 
Sanscrit root mand, from which Pott derives the Latin mundus {Etym. 
Forsch., th. i.,s. 240), combines the double signification of shining and 
adorning. Loka designates in Sanscrit the world and people in general, 
in the same manner as the French word monde, and is derived, accord- 
ing to Bopp, from Idk (to see and shine); it is the same with the Scla- 
vonic root swjet, which means both light and icorld. (Grimm, Deutsche 
Gramm., b. iii., s. 394 — German Grammar.) The word icelt, which 
the Germans make use of at the present day, and which was weralt in 
old German, toorold in old Saxon, and veruld in Anglo-Saxon, was, ac- 
cording to .Tames Grimm's interpi-etation, a period ol time, an age (««- 
cnlum), rather than a term used for the world in space. The Etruscans 
figured to themselves mundus as an inverted dome, symmetrically op- 
posed to the celestial vault (Otfried MUller's Etrusken, th. ii., s. 96, 
&c.). Taken in a still more hmited sense, the word appears to have 
signified among the Goths the terrestrial surface girded by seas (marei, 
meri), the merigard, literally, garden of seas. 



INTRODUCTION. 71 

of nature, Parmenides and Empedocles. and from thence into 
the works of prose writers. We will not here enter into a 
discussion of the manner in which, according to the Pythago- 
rean views, Philolaiis distinguishes between Olympus, Uranus, 
or the heavens, and Cosmos, or how the same word, used in 
a plural sense, could be applied to certain heavenly bodies 
(the planets) revolving round one central focus of the world, 
or to groups of stars. In this work I use the word Cosmos in 
conformity with the Hellenic usage of the term subsequently 
to the time of Pythagoras, and in accordance with the precise 
definition given of it in the treatise entitled De Mmido, which 
was long erroneously attributed to Aristotle. It is the assem- 
blage of all things in heaven and earth, the universality of 
created things constituting the perceptible world. If scientific 
terms had not long been diverted from their true verbal sig- 
nification, the present work ought rather to have borne the 
title of Cosmography, divided into Uranography and Geog- 
raj)hy. The Romans, in their feeble essays on philosophy, ^ 
imitated the Greeks by applying to the universe the term 
inundus, which, in its primary meaning, indicated nothing 
more than ornament, and did not even imply order or regu- 
larity in the disposition of parts. It is probable that the in- 
troduction into the language of Latium of this technical term 
as an equivalent for Cosmos, in its double signification, is due 
to Ennius,* who was a follower of the Italian school, and the 
translator of the writings of Epicharmus and some of his pu 
pils on the Pythagorean philosophy. 

We would first distinguish between the physical history and 
the physical description of the world. The former, conceived 
in the most general sense of the word, ought, if materials for 
writing it existed, to trace the variations experienced by the 
universe in the course of ages from the new stars which have 
suddenly appeared and disappeared in the vault of heaven, 
from nebula} dissolving or condensing — to the first stratum of 
cryptogamic vegetation on the still imperfectly cooled surface 
of the earth, or on a reef of coral uplifted from the depths of 
ocean. The physical description of the ivorld presents a pic- 
ture of all that exists in space — of the simultaneous action of 

* See, on Ennius, the ingenious researches of Leopold Krahnev, in 
liis Grundlinien ziir GeschicJite des Verfalls der Romischen Staats-Rcii 
gion, 1837, s. 41-45 (Outlines of the History of the Decay of the EstaU 
lished Religion among the Romans). In all probability, Ennius did not 
quote from writings of Epicharmus himself, but from poems composed 
La the name of that philosopher, and in accordance wi'h his views 



72 COSMOS. 

natural forces, together with the phenomena which they pro- 
duce. 

But if we would correctly comprehend nature, we must not 
entirely or absolutely separate the consideration of the present 
state of things from that of the successive phases through 
which they have passed. We can not form a just conception 
of their nature without looking back on the mode of their for- 
mation. It is not organic matter alone that is continually un- 
dergoing change, and being dissolved to form new combina- 
tions. The globe itself reveals at every phase of its existence 
the mystery of its former conditions. 

We can not survey the crust of our planet without recog- 
nizing the traces of the prior existence and destruction of an 
organic world. The sedimentary rocks present a succession 
of organic forms, associated in groups, Avhich have successive- 
ly displaced and succeeded each other. The different super 
imposed strata thus display to us the faunas and floras of dif- 
ferent epochs. In this sense the description of nature is inti 
mately connected with its history ; and the geologist, who is 
guided by the connection existing among the facts observed, 
can not form a conception of the present without pursuing, 
through countless ages, the history of the past. In tracing 
the physical delineation of the globe, we behold the present 
and the past reciprocally incorporated, as it were, with one 
another ; for the domain of nature is like that of languages, in 
which etymological research reveals a successive development, 
by showing us the primary condition of an idiom reflected in 
the forms of speech in use at the present day. The study of 
the material world renders this reflection of the past peculiar- 
ly manifest, by displaying in the process of formation rocks of 
eruption and sedimentary strata similar to those of former 
ages. If I may be allowed to borrow a striking illustration 
from the geological relations by which the physiognomy of a 
country is determined, I would say that domes of trachyte, 
cones of basalt, lava streams {coulees) of amygdaloid with 
elongated and parallel pores, and white deposits of pumice, 
intermixed with black scoriae, animate the scenery by the as- 
sociations of the past which they awaken, actmg upon the 
imagination of the enlightened observer like traditional records 
of an earlier world. Their form is their history. 

The sense in which the Greeks and Romans originally em- 
ployed the word history proves that they too were intimately 
convinced that, to form a complete idea of the present state 
of the universe, it was necessary to consider it in its successive 



INTRODUCTION. 73^ 

phases. It is not, however, in the definition given by Vale- 
lius Flaccus,*' but in the zoological writings of Aristotle, that 
the word history presents itself as an exposition of the results 
of experience and observation. The physical description of 
the word by Pliny the elder bears the title of Natural His- 
tory, while in the letters of his nephew it is designated by the 
nobler terra of History of Nature. The earlier Greek his- 
torians did not separate the descriptions of countries from the 
narrative of events of which they had been the theater. With 
these writers, physical geography and history were long inti- 
mately associated, and remained simply but elegantly blended 
until the period of the development of political interests, when 
the agitation in which the lives of men were passed caused 
the geographical portion to be banished from the history of 
nations, and raised into an independent science. 

It remains to be considered whether, by the operation of 
thought, we may hope to reduce the immense diversity of 
phenomena comprised by the Cosmos to the unity of a princi- 
ple, and the evidence ajSbrded by rational truths. In the 
present state of empirical knowledge, we can scarcely flatter 
ourselves Avith such a hope. Experimental sciences, based 
on the observation of the external world, can not aspire to 
completeness ; the nature of things, and the imperfection of 
our organs, are alike opposed to it. We shall never succeed 
in exhausting the immeasurable riches of nature ; and no gen- 
eration of men will ever have cause to boast of bavins: com- 
prehended the total aggregation of phenomena. It is only by 
distributing them into groups that we have been able, in the 
case of a few, to discover the empire of certain natural laws, 
grand and simple as nature itself. The extent of this empire 
will no doubt increase in proportion as physical sciences are 
more perfectly developed. Striking proofs of this advance- 
ment have been made manifest in our own day, in the phe- 
nomena of electro-magnetism, the propagation of luminous 
waves and radiating heat. In the same manner, the fruitful 
doctrine of evolution shows us how, in organic development, 
all that is formed is sketched out beforehand, and how the 
tissues of vegetable and animal matter uniformly arise from 
the multiplication and transformation of cells. 

The generalization of laws, which, being at first bounded 
by narrow limits, had been applied solely to isolated groups 
of phenomena, acquires in time more marked gradations, and 
gains in extent and certainty as long as the process of reason* 

* Aul. Gell.. Noct. Alt., v., 18. 

Vol. I— D 



74 COSMOS. 

ing is applied strictly to analogous phenomena ; but as soon 
as dynamical views prove insufficient M'here the specific prop- 
erties and heterogeneous nature of matter come into play, it is 
to he feared that, by persisting in the pursuit of laws, we may 
find our course suddenly arrested by .an impassable chasm. 
The principle of unity is lost sight of, and the guiding clew 
is rent asunder whenever any specific and peculiar kind of 
action manifests itself amid the active forces of nature. The 
law of equivalents and the numerical proportions of composi- 
tion, so happily recognized by modern chemists, and proclaimed 
under the ancient form of atomic symbols, still remains isola- 
ted and independent of mathematical laws of motion and grav- 
itation. 

Those productions of nature which are objects of direct ob- 
servation may be logically distributed in classes, orders, and 
families. This form of distribution undoubtedly sheds some 
light on descriptive natural history, but the study of organized 
bodies, considered in their linear connection, although it may 
impart a greater degree of unity and simplicity to the distri- 
bution of groups, can not rise to the height of a classification 
based on one sole principle of composition and internal organ- 
ization. As different gradations are presented by the laws 
of nature according to the extent of the horizon, or the limits 
of the phenomena to be considered, so there are likewise dif- 
ferently graduated phases in the investigation of the external 
world. Empiricism originates in isolated views, which are 
subsequently grouped according to their analogy or dissimilar- 
ity. To direct observation succeeds, although long afterward, 
the wish to prosecute experiments ; that is to say, to evoke 
phenomena under different determined conditions. The ra- 
tional experimentalist does not proceed at hazard, but acts 
under the guidance of hypotheses, founded on a half indistinct 
and more or less just intuition of the connection existing among 
natural objects or forces. That which has been conquered 
by observation or by means of experiments, leads, by analysis 
and induction, to the discovery of empirical laws. These are 
the phases in human intellect that have marked the different 
epochs in the life of nations, and by means of which that great 
mass of facts has been accumulated which constitutes at the 
present day the solid basis of the natural sciences. 

Two forms of abstraction conjointly regulate our knowl- 
edge, namely, relations of quantity, comprising ideas of num- 
ber and size, and relations of quality, embracing the consider- 
ation of the specific properties and the heterogeneous nature 



INTRODUCTION. 76 

of matter. The former, as being more accessible to the exer 
cise of thought, appertains to mathematics ; the latter, from 
its apparent mysteries and greater difficulties, falls under the 
domain of the chemical sciences. In order to submit phe- 
nomena to calculation, recourse is had to a hypothetical con- 
struction of matter by a combination of molecules and atoms, 
whose number, form, position, and polarity determine, modify, 
or vary phenomena. 

The mythical ideas long entertained of the imponderable 
substances and vital forces peculiar to each mode of organiza- 
tion, have complicated our views generally, and shed an un- 
certain light on the path we ought to pursue. 

The most various forms of intuition have thus, age aftei 
age, aided in augmenting the prodigious mass of empirical 
knowledge, which in our own day has been enlarged with 
ever-increasing rapidity. The investigating spirit of man 
strives from time to time, with varying success, to break 
through those ancient forms and symbols invented, to subject 
rebellious matter to rules of mechanical construction. 

We are still very far from the time when it will be possi- 
ble for us to reduce, by the operation of thought, all that we 
perceive by the senses, to the unity of a rational principle. 
It may even be doubted if such a victory could ever be 
achieved in the field of natural philosophy. The complica- 
tion of phenomena, and the vast extent of the Cosmos, would 
seem to oppose such a result ; but even a partial solution of 
the problem — the tendency toward a comprehension of the 
phenomena of the universe — will not the less remain the eter- 
nal and sublime aim of every investigation of nature. 

In conformity with the character of my former writings, as 
well as with the labors in which I have been engaged during 
my scientific career, in measurements, experiments, and the 
investigation of facts, I limit myself to the domain of empirical 
ideas. 

The exposition of mutually connected facts does not exclude 
the classification of phenomena according to their rational con- 
nection, the generalization of many specialities in the great 
mass of observations, or the attempt to discover laws. Con- 
ceptions of the universe solely based upon reason, and the 
principles of speculative philosophy, would no doubt assign a 
still more exalted aim to the science of the Cosmos. I am far 
from blaming the efforts of others solely because their success 
has hitherto remained very doubtful. Contrary to the wishes 
and counsels of those profound and powerful thinkers who 



76 COSMOS. 

have given new life to speculations which were already fa- 
miliar to the ancients, systems of natural philosophy have in 
our own country for some time past turned aside the minds 
of men from the graver study of mathematical and physical 
sciences. The abuse of better powers, which has led many 
of our noble but ill-judging youth into the saturnalia of a pure- 
ly ideal science of nature, has been signalized by the intoxica- 
tion of pretended conquests, by a novel and fantastically sym- 
bolical phraseology, and by a predilection for the formulae of 
a scholastic rationalism, more contracted in its views than 
any known to the Middle Ages. I use the expression " abuse 
of better powers," because superior intellects devoted to phil- 
osophical pursuits and experimental sciences have remained 
strangers to these saturnalia. The results yielded by an earn- 
est investigation in the path of experinient can not be at va- 
riance with a true philosophy of nature. If there be any 
contradiction, the fault must lie either in the unsoundness of 
speculation, or in the exaggerated pretensions of empiricism, 
which thinks that more is proved by experiment than is act- 
ually derivable from it. 

External nature may be opposed to the intellectual world, 
as if the latter were not comprised within the limits of the 
former, or nature may be opposed to art when the latter is 
defined as a manifestation of the intellectual power of man ; 
but these contrasts, which we find reflected in the most cul- 
tivated languages, must not lead us to separate the sphere of 
nature from that of mind, since such a separation would re- 
duce the physical science of the world to a mere aggregation 
of empirical specialities. Science does not present its.elf to 
man until mind conquers matter in striving to subject the 
result of experimental investigation to rational combinations. 
Science is the labor of mind applied to nature, but the ex- 
ternal world has no real existence for us beyond the image 
reflected within ourselves through the medium of the senses. 
As intelligence and forms of speech, thought and its verbal 
symbols, are united by secret and indissoluble links, so does 
the external world blend almost unconsciously to ourselves 
with our ideas and feelings. " External phenomena," says 
Hegel, in his Philosophy of History, " are in some degree 
translated in our inner representations. ' ' The objective world, 
conceived and reflected, within us by thought, is subjected to 
the eternal and necessary conditions of our intellectual being. 
The activity of the mind exercises itself on the elements fur- 
nished to it by the perceptions of the senses. Thus, in the 



INTRODUCTION. 77 

early ages of mankind, there manifests itself in the simple in- 
tuition of natm*al facts, and in the efforts made to compre- 
hend them, the germ of the philosophy of nature. These 
ideal tendencies vary, and are more or less powerful, accord- 
ing to the individual characteristics and moral dispositions of 
nations, and to the degrees of their mental culture, whether 
attained amid scenes of nature that excite or chill the imag- 
ination. 

History has preserved the record of the numerous attempts 
that have been made to form a rational conception of the 
whole world of phenomena, and to recognize in the universe 
the action of one sole active force by which matter is pene- 
trated, transformed, and animated. These attempts are traced 
in classical antiquity in those treatises on the principles of 
things which emanated from the Ionian school, and in which 
all the phenomena of nature were subjected to hazardous 
speculations, based upon a small number of observations. By 
degrees, as the influence of great historical events has favored 
the development of every branch of science supported by ob- 
servation, that ardor has cooled which formerly led men to 
seek the essential nature and connection of things by ideal 
construction and in purely rational principles. In recent 
times, the mathematical portion of natural philosophy has 
been most remarkably and admirably enlarged. The method 
and the instrument (analysis) have been simultaneously per- 
fected. That which has been acquired by means so different 
— by the ingenious application of atomic suppositions, by the 
more general and intimate study of phenomena, and by the 
improved construction of new apparatus — is the common prop- 
erty of mankind, and should not, in our opinion, now, more 
than in ancient times, be withdrawn from the free exercise of 
speculative thought. 

It can not be denied that in this process of thought the 
results of experience have had to contend with many disad- 
vantages ; we must not, therefore, be surprised if, in the per- 
petual vicissitude of theoretical views, as is ingeniously ex- 
pressed by the author of Giordano Bi'uno,^ " most men see 
nothing in philosophy but a succession of passing meteors, 
while even the grander forms in which she has revealed her- 
self share the fate of comets, bodies that do not rank in pop- 
ular opinion among the eternal and permanent works of na- 

* SchelUug's Bruno, TJeher das Goitliche und Naturaliche Princip 
der Dingc, $ 181 (Bruno, on the Divine and Natural Principle of 
Things) 



78 coSxMos. 

ture, but are regarded as mere fugitive apparitions of igiioo«/s 
vapor." We would here remark that the abuse of thought, 
and the false track it too often pursues, ought not to sanctian 
an opinion derogatory to intellect, vi^hich would imply that 
the domain of mind is essentially a world of vague fantastic 
illusions, and that the treasures accumulated by laborious ob- 
servations in philosophy are powers hostile to its own empire. 
It does not become the spirit which characterizes the present 
age distrustfully to reject every generalization of views and 
every attempt to examine into the nature of things by the 
process of reason and induction. It would be a denial of the 
dignity of human nature and the relative importance of the 
faculties with which we are endowed, were we to condemn 
at one time austere reason engaged in investigating causes 
and their mutual connections, and at another that exercise of 
the imagination which prompts and excites discoveries by its 
creative powers. 



COSMOS. 



DELINEATION OF NATURE. GENERAL REVIEW OF 
NATURAL PHENOMENA. 

When the human mind first attempts to subject to its con- 
trol the world of physical phenomena, and strives by medita- 
tive contemplation to penetrate the rich luxuriance of living 
nature, and the mingled web of free and restricted natural 
forces, man feels himself raised to a height from whence, as 
he embraces the vast horizon, individual things blend together 
in varied groups, and appear as if shrouded in a vapory vail. 
These figurative expressions are used in order to illustrate the 
point of view from whence we would consider the universe 
both in its celestial and terrestrial sphere. I am not insen- 
sible of the boldness of such an undertaking. Among all the 
forms of exposition to which these pages are devoted, there 
is none more difficult than the general delineation of nature, 
which we purpose sketching, since we must not allow our- 
selves to be overpowered by a sense of the stupendous rich- 
ness and variety of the forms presented to us, but must dwell 
only on the consideration of masses either possessing actual 
magnitude, or borrowing its semblance from the associations 
aAvakened within the subjective sphere of ideas. It is by a 
separation and classification of phenomena, by an intuitive in- 
sight into the play of obscure forces, and b/ animated expres- 
sions, in which the perceptible spectacle is i\ fleeted with vivid 
truthfulness, that we may hope to compreh^^nd and describe 
the universal all (to Tray) in a manner worthy of the dignity 
of the word Cosmos m its signification of tiniverse, order of 
the U'orld, and adornment of this universal order. May the 
ijumeasurable diversity of phenomena which crowd into the 
picture of nature in no way detract from that harmonious im- 
pression of rest and unity v/hich is the ultimate object of every 
literary or purely artistical composition. 

Beginning with the depths of space and the regions of re- 
motest nebulse, Vv-e will gradually descend through the starry 
zone to which our solar system belongs, to our own terrestrial 
spheroid, circled by air and ocean, there to direct our atten- 



80 COSMOS 

tion to its form, temperature, and magnetic tension, and to 
consi'ler the fullness of organic life unfolding itself upon its 
surface beneath the vivifying influence of light. In this man- 
ner a picture of the world may, with a few strokes, be made 
to include the realms of infinity no less than the minute mi- 
croscopic animal and vegetable organisms which exist in stand- 
ing waters and on the weather-beaten surface of our rocks. 
All that can be perceived by the senses, and all that has been 
accumulated up to the present day by an attentive and vari- 
ously directed study of nature, constitute the materials from 
which this representation is to be drawn, whose character is 
an evidence of its fidelity and truth. But the descriptive pic- 
ture of nature which we purpose drawing must not enter too 
fully into detail, since a minute enumeration of all vital forms, 
natural objects, and processes is not requisite to the complete- 
ness of the undertaking. The delineator of nature must re- 
sist the tendency toward endless division, in order to avoid 
the dangers presented by the very abundance of our empirical 
knowledge. A considerable portion of the qualitative proper^, 
ties of matter — -or, to speak more in accordance with the lan- 
guage of natural philosophy, of the qualitative expression of 
forces — is doubtlessly still unknown to us, and the attempt 
perfectly to represent unity in diversity must therefore neces- 
sarily prove unsuccessful. Thus, besides the pleasure derived 
from acquired knowledge, there lurks in the mind of man, 
and tinged with a shade of sadness, an unsatisfied longing for 
something beyond the present — a striving towaixl regions yet 
unknown and unopened. Such a sense of longing binds still 
■aster the links which, in accordance with the supreme laws 
of our being, connect the material with the ideal world, and 
animates the mysterious relation existing between that which 
the mind receive^ from without, and that which it reflects 
from its own dej ths to the external world. If, then, nature 
(understanding by the term all natural objects and phenomena) 
be illimitable in extent and contents, it likewise presents it- 
self to the haman intellect as a problem which can not be 
grasped, a.nd whose solution is impossible, since it requires a 
knowledge of che combined action of all natural forces. Such 
an acknowledgment is due where the actual state and pro- 
spective development of phenomena constitute the sole objects 
of direct investigation, which does not venture to depart from 
the strict rules of induction. But, although the incessant ef- 
fort to embrace nature in its universality may remain unsatis- 
fied, the history of the contemplation of the universe (which 



DELINEATION OF NATURE. 81 

Will be considered in another part of this work) will teach us 
how, in the course of ages, mankind has gradually attained 
to a partial insight into the relative dependence of phenomena. 
My duty is to depict the results of our knowledge in all their 
bearings with reference to the present. In all that is subject 
to motion and change in space, the ultimate aim, the very ex- 
pression of physical laws, depend upon inean mimerical value?,. 
which show us the constant amid change, and the stable amid 
apparent fluctuations of phenomena. Thus the progress of 
modern physical science is especially characterized by the at- 
tainment and the rectification of the mean values of certain 
quantities by means of the processes of weighing and meas- 
uring ; and it may be said, that the only remaining and wide- 
ly-difiused hieroglyphic characters still in our writing — nimi- 
bers — appear to us again, as powers of the Cosmos, although 
in a wider sense than that applied to them by the Italian 
School. 

The earnest investigator delights in the simplicity of nu- 
merical relations, indicating the dimensions of the celestial 
regions, the magnitudes and periodical disturbances of the 
heavenly bodies, the triple elements of terrestrial magnetism, 
the mean pressure of the atmosphere, and the quantity of heat 
which the sun imparts in each year, and in every season of the 
year, to all points of the solid and liquid surface of our planet. 
These sources of enjoyment do not, however, satisfy the poet 
of Nature, or the mind of the inquiring many. To both of 
these the present state of science appears as a blank, now that 
she answers doubtingly, or wholly rejects as unanswerable, 
questions to which former ages deemed they could furnish 
satisfactory rephes. In her severer aspect, and clothed with 
less luxuriance, she shows herself deprived of that seductive 
charm with which a dogmatizing and symbolizing physical 
philosophy knew how to deceive the understanding and give 
the rein to imagination. Long before the discovery of the 
New World, it was believed that new lands in the Far West 
might be seen from the shores of the Canaries and the Azores. 
These illusive images were owing, not to any extraordinary 
refraction of the rays of light, but produced by an eager long- 
ing for the distant and the unattained. The philosophy of 
the Greeks, the physical views of the Middle Ages, and even 
those of a more recent period, have been eminently imbued 
with the charm springing from similar illusive phantoms of 
the imagination. At the limits of circumscribed knowledge, 
as from some lofty island shore, the eye delights to penetrate 

D2 



82 COSMOS. 

to distant regions. The belief in the uncommon and the won- 
derful lends a definite outline to every manifestation of ideal 
creation ; and the realm of fancy — a fairy-land of cosmolog- 
ical, geognostical, and magnetic visions — becomes thus invol- 
untarily blended vv^ith the domain of reaUty. 

Nature, in the manifold signification of the word — whether 
considered as the universality of all that is and ever will be — 
as the inner moving force of all phenomena, or as their mys- 
terious prototype — reveals itself to the simple mind and feel- 
ings of man as something earthly, and closely allied to him- 
self It is only within the animated circles of organic struc- 
ture that we feel ourselves peculiarly at home. Thus, 
wherever the earth unfolds her fruits and flowers, and gives 
food to countless tribes of animals, there the image of nature 
impresses itself most vividly upon our senses. The impression 
thus produced upon our minds limits itself almost exclusively 
to the reflection of the earthly. The starry vault and the 
wide expanse of the heavens belong to a picture of the uni- 
verse, in which the magnitude of masses, the number of con- 
gregated suns and faintly glimmering nebulae, although they 
excite our wonder and astonishment, manifest themselves to 
us in apparent isolation, and as utterly devoid of all evidence 
of their being the scenes of organic life. Thus, even in the 
earliest physical views of mankind, heaven and earth have 
been separated and opposed to one another as an upper and 
lower portion of space. If, then, a picture of nature were to 
correspond to the requirements of contemplation by the senses, 
it ought to begin with a delineation of our native earth. It 
should depict, first, the terrestrial planet as to its size and 
form ; its increasing density and heat at increasing depths in 
its superimposed solid and liquid strata ; the separation of sea 
and land, and the vital forms animating both, developed in 
the cellular tissues of plants and animals ; the atmospheric 
ocean, with its waves and currents, through which pierce the 
forest-crowned summits of our mountain chains. After this 
delineation of purely telluric relations, the eye would rise to 
the celestial regions, and the Earth would then, as the well- 
known seat of organic development, be considered as a planet, 
occupying a place in the series of those heavenly bodies which 
circle round one of the innumerable host of self-luminous stars. 
This succession of ideas indicates the course pursued in the 
earliest stages of perceptive contemplation, and reminds us of 
the ancient conception of the " sea-girt disk of earth," sup- 
porting the vault of heaven. It begins to exercise its action 



at the spot where it originated, and passes from the consider- 
ation of the known to the unknown, of the near to the distant 
It corresponds with the method pursued in our elementary 
works on astronomy (and which is so admirable in a mathe- 
matical point of view), of proceeding from the apparent to the 
real movements of the heavenly bodies. 

Another course of ideas must, however, be pursued in a 
work which proposes merely to give an exposition of what is 
known — of what may in the present state of our knowledge 
be regarded as certain, or as merely probable in a greater or 
lesser deofree — and does not enter into a consideration of the 
proofs on which such results have been based. Here, there- 
fore, we do not proceed from the subjective point of view of 
human interests. The terrestrial must be treated only as a 
part, subject to the whole. The view of nature ought to be 
grand and free, uninfluenced by motives of proximity, social 
sympathy, or relative utility. A physical cosmography — a 
picture of the universe — does not begin, therefore, with the 
terrestrial, but with that which fills the regions of space. But 
as the sphere of contemplation contracts in dimension our per- 
ception of the richness of individual parts, the fullness of phys- 
ical phenomena, and of the heterogeneous properties of mat- 
ter becomes enlarged. From the regions in which we rec- 
ognize only the dominion of the laws of attraction, Ave de- 
scend to our own planet, and to the intricate play of terrestrial 
forces. The method here described for the delineation of na- 
ture is opposed to that which must be pursued in establish- 
ino- conclusive results. The one enumerates what the other 
demonstrates. 

Man learns to know the external world through the organs 
of the senses. Phenomena of light proclaim the existence of 
matter in remotest space, and the eye is thus made the me- 
dium through which we may contemplate the universe. The 
discovery of telescopic vision more than two centuries ago, has 
transmitted to latest generations a power whose limits are as 
yet unattained. 

The first and most general consideration in the Cosmos is 
that of the contents of space — the distribution of matter, or 
of creation, as we are wont to designate the assemblage of all 
that is and ever will be developed. We see matter either 
agglomerated into rotating, revolving spheres of different dens- 
ity and size, or scattered through space in the form of self- 
luminous vapor. If we consider first the cosmical vapor dis 
persed in definite nebulous spots, its state of aggregation will 



84 COSMOS. 

appear constantly to vary, sometimes appearing separated into 
round or elliptical disks, single or in pairs, occasionally con- 
nected by a thread of light ; while, at another time, these* 
nebulae occur in forms of larger dimensions, and are either 
elongated, or variously branched, or fan-shaped, or appear like 
well-defined rings, inclosing a dark interior. It is conjectured 
that these bodies are undergoing variously developed formative 
processes, as the cosmical vapor becomes condensed in con- 
formity with the laws of attraction, either round one or more 
of the nuclei. Between two and three thousand of such un- 
resolvabie nebulae, in which the most powerful telescopes have 
hitherto been unable to distinguish the presence of stars, have 
been counted, and their positions determined. 

The genetic evolution — that perpetual state of development 
which seems to affect this portion of the regions of space — 
has led philosophical observers to the discovery of the analogy 
existing among organic phenomena. As in our forests we see 
the same kind of tree in all the various stages of its growth, 
and are thus enabled to form an idea of progressive, vital de- 
velopment, so do we also, in the great garden of the universe, 
recognize the most different phases of sidereal formation. The 
process of condensation, which formed a part of the doctrines 
of Anaximenes and of the Ionian School, appears to be going 
on before our eyes. This subject of investigation and conject- 
ure is especially attractive to the imagination, for in the study 
of the animated circles of nature, and of the action of all the 
moving forces of the universe, the charm that exercises the 
most powerful influence on the mind is derived less from a 
knowledge of that which is than from a perception of that 
which will be, even though the latter be nothing more than 
a new condition of a known material existence ; for of actual 
creation, of origin, the beginning of existence from non-exist- 
ence, we have no experience, and can therefore form no con- 
ception. 

A comparison of the various causes influencing the develop- 
ment manifested by the greater or less degree of condensation 
in the interior of nebulae, no less than a successive course of 
direct observations, have led to the belief that changes of form 
have been recognized first in Andromeda, next in the constel- 
lation Argo, and in the isolated filamentous portion of the 
nebula in Orion. But want of uniformity in the power of the 
instruments employed, different conditions of our atmosphere, 
and other optical relations, render a part of the results invalid 
as historical evidence. 



CELESTIAL PHENOMENA. 85 

Nebulous stars must not be confounded either with irreffu- 
larly-shaped nebulous spots, properly so called, whose separate 
parts have an unequal degree of brightness (and which may, 
perhaps, become concentrated into stars as their circumference 
contracts), nor with the so-called planetary nebulae, whose cir- 
cular or slightly oval disks manifest in all their parts a per- 
fectly uniform degree of faint light. Nebulous stars are not 
merely accidental bodies projected upon a nebulous ground, 
but are a part of the nebulous matter constituting one mass 
with the body which it surrounds. The not unfrequently con- 
siderable magnitude of their apparent diameter, and the re- 
mote distance from which they are revealed to us, show that 
both the planetary nebulte and the nebulous stars must be of 
enormous dimensions. New and ingenious considerations of 
the different influence exercised by distance^ on the intensity 
of light of a disk of appreciable diameter, and of a single self- 
luminous point, render it not improbable that the planetary 
nebula? are very remote nebulous stars, in which the differ- 
ence between the central body and the surrounding nebulous 
covering can no longer be detected by our telescopic instru- 
ments. 

The magnificent zones of the southern heavens, between 
50° and 80°, are especially rich in nebulous stars, and in com- 
pressed unresolvable nebulae. The larger of the two Magel- 
lanic clouds, which circle round the starless, desert pole of the 
south, appears, according to the most recent researches,! as 
" a collection of clusters of stars, composed of globular clusters 
and nebulae of different magnitude, and of large nebulous spots 

* The optical cousiderations relative to the difTerence presented by 
a single luminous point, and by a disk subtending an appreciable angle, 
in which the intensity of light is constant at every distance, are explain- 
ed in Arago's Analyse des Travaux de Sir William Herschel (Annuaire 
du Bvreaii des Lang., 1842, p. 410-412, and 441). 

t The twro Magellanic clouds, Nubecula major and Nubecula minor, 
are very remarkable objects. The larger of the two is an accumulated 
mass of stars, and consists of clusters of stars of irregular form, either 
conical masses or nebulae of different magnitudes and degrees of con- 
densation. This is interspersed with nebulous spots, not resolvable 
into stars, but which are probably star dust, appearing only as a general 
radiance upon the telescopic field of a twenty-feet reflector, and form- 
ing a luminous ground on which other objects of striking and inde- 
scribable form are scattered. In no other portion of the heavens are 
so many nebulous and stellar masses thronged together in an equally 
small space. Nubecula minor is much less beautiful, has more unre- 
solvable nebulous light, while the stellar masses are fewer and fainter 
in intensity. — (From a letter of Sir John Herschel, Feldhuysen, Cape 
of Good Hope, 13th June, 1836.) 



86 COSMOS. 

not resolvable, which, producing a general brightness in the 
field of view, form, as it were, the back-ground of the picture." 
The appearance of these clouds, of the brightly-beaming con- 
stellation Argo, of the Milky Way between Scorpio, the Cen- 
taur, and the Southern Cross, the picturesque beauty, if one 
may so speak, of the whole expanse of the southern celestial 
hemisphere, has left upon my mind an ineffaceable impression. 
The zodiacal light, which rises in a pyramidal form, and con- 
stantly contributes, by its mild radiance, to the external beauty 
of the tropical nights, is either a vast nebulous ring, rotating 
between the Earth and Mars, or, less probably, the exterior 
stratum of the solar atmosphere. Besides these luminous clouds 
and nebulse of definite form, exact and corresponding observa* 
tions indi^ccxe the existence and the general distribution of an 
apparently non-luminous, infinitely-divided matter, which pos 
sesses a force of resistance, and manifests its presence in Encke's, 
and perhaps also in Biela's comet, by diminishing their eccen- 
tricity and shortening their period of revolution. Of this im- 
peding, ethereal, and cosmical matter, it may be supposed that 
it is in motion ; that it gravitates, notwithstanding its original 
tenuity ; that it is condensed in the vicinity of the great mass 
of the Sun ; and, finally, that it may, for myriads of ages, 
have been augmented by the vapor emanating from the tails 
of comets. 

If we now pass from the consideration of the vaporous mat- 
ter of the immeasurable regions of space {ovpavov ^oprog)* 
— whether, scattered without definite form and limits, it ex- 
ists as a cosmical ether, or is condensed into nebulous spots, 
and becomes comprised among the solid agglomerated bodies 
of the universe — we approach a class of phenomena exclusive- 
ly designated by the term of stars, or as the sidereal world. 

* I should have made use, in the place of garden of the universe, of 
the beautiful expression xoprog ovpavov, borrowed by Hesychius fi-om 
an unknown poet, if ;:j;6prof had not rather signified in general an in- 
closed space. The connection with the German garten and the En- 
glish garden, gards in Gothic (derived, according to Jacob Grimm, from 
gairdan, to gird), is, however, evident, as is likewise the affinity with 
the Sclavonic grad, gorod, and as Pott remarks, in his Etymol. Forschun- 
gen, th. i., s. 144 (Etymol. Researches), with the Latin chars, whence 
we have the Spanish corte, the French cour, and the English word court, 
together with the Ossetic khart. To these may be further added the 
Scandinavian gard,^ gdrd, a place inclosed, as a court, or a country 
seat, and the Persian gerd, gird, a district, a circle, a princely country 
Beat, a castle or city, as we find the term applied to the names of places 
in Firdusi's Schahnameh, as Siyawakschgird, Darabgird, &c. 

* (This word is written ^aarrf in the Danish.] — TV. ^ 



CELESTIAL PHENOMENA. 87 

Here, too, we find diflerences existing in the solidity or density 
of the spheroid ally agglomerated matter. Our own solar sys- 
tem presents all stages of mean density (or of the relation of 
volume to 7?iass.) On comparing the planets from Mercury 
to Mars with the Sun and with Jupiter, and these two last 
named with the yet inferior density of Saturn, we arrive, by 
a descendino- scale — to draw our illustration from terrestrial 
substances — at the respective densities of antimony, honey, 
water, and pine wood. In comets, which actually constitute 
the most considerable portion of our solar system with respect 
to the number of individual forms, the concentrated part, 
usually termed the head, or nucleus, transmits sidereal light 
unimpaired. The mass of a comet probably in no case equals 
the five thousandth part of that of the earth, so dissimilar are 
the formative processes manifested in the original and perhaps 
still progressive agglomerations of matter. In proceeding from 
general to special considerations, it was particularly desirable 
to draw attention to this diversity, not merely as a possible, 
but as an actually proved fact. 

The purely speculative conclusions arrived at by Wright, 
Kant, and Lambert, concerning the general structural ar- 
rangement of the universe, and of the distribution of matter 
in space, have been confirmed by Sir William Herschel, on 
the more certain path' of observation and measurement. That 
great and enthusiastic, although cautious observer, was the 
first to sound the depths of heaven in order to determine the 
limits and form of the starry stratum which we inhabit, and 
he, too, was the first who ventured to throw the light of inves- 
tigation upon the relations existing between the position and 
distance of remote nebulae and our own portion of the sidereal 
universe. William Herschel, as is well expressed in the ele- 
gant inscription on his monument at Upton, broke through the 
inclosures of heaven {codorum perrupit claustra), and, like 
another Columbus, penetrated into an unknown ocean, from 
which he beheld coasts and groups of islands, whose true po- 
sition it remains for future ages to determine. 

Considerations regarding the different intensity of light in 
stars, and their relative number, that is to say, their numeric- 
al frequency on telescopic fields of equal magnitude, have led 
to the assumption of unequal distances and distribution in space 
in the strata which they compose. Such assumptions, in as 
far as they may lead us to draw the limits of the individual 
portions of the universe, can not ofi^er the same degree of math- 
ematical certainty as that which may be attained in all that 



88 COSMOS. 

relaies to our solar system, whether we consider the rotation 
of double stars with unequal velocity round one common cen- 
ter of gravity, or the apparent or true movements of all the 
heavenly bodies. If we take up the physical description of 
the universe from the remotest nebulae, we may be inclined 
to compare it with the mythical portions of history. The one 
begins L- the obscurity of antiquity, the other in that of inac- 
cessible space ; and at the point where reality seems to flee 
before us, imagination becomes doubly incited to draw from 
its own fullness, and give definite outline and permanence to 
the changing forms of objects. 

If we compare the regions of the universe with one of the 
island- studded seas of our own planet, we may imagine mat- 
ter to be distributed in groups, either as unresolvable nebulaj 
of different ages, condensed around one or more nuclei, or as 
already agglomerated into clusters of stars, or isolated sphe- 
roidal bodies. The cluster of stars, to which our cosmical isl- 
and belongs, forms a lens-shaped, flattened stratum, detached 
on every side, whose major axis is estimated at seven or eight 
hundred, and its minor one at a hundred and fifty times the 
distance of Sirius. It would appear, on the supposition that 
the parallax of Sirius is not greater than that accurately de- 
termined for the brightest star in the Centaur (0"-9128), that 
hght traverses one distance of Sirius in three years, while it 
also follows, from Bessel's earlier excellent Memoir* on the 
parallax of the remarkable star 61 Cygni (0"-3483), (whose 
considerable motion might lead to the inference of great prox- 
imity), that a period of nine years and a quarter is required 
for the transmission of light Irom this star to our planet. Our 
starry stratum is a disk of inconsiderable thickness, divided a 

* See Maclear's " Results from 1839 to 1840," in the Trans, of the 
Astronomical Soc, vol. xii., p. 370, on a Centauri, the probable mean' 
error being 0"-0640. For 61 Cygni, see Bessel, in Schumacher's Jahr- 
buch, 1839, s. 47, and Schumacher's Astron. Nachr., bd. xviu., s. 401, 
402, probable mean error, 0"-0141. With reference to the relative 
distances of stars of different magnitudes, how those of the third mag- 
nitude may probably be three times more remote, and the manner in 
which we represent to ourselves the material arrangenient of the starry 
strata, I have found the following remarkable passage in Kepler's 
Epitome Astronomies Copernicance, 1618, t. i., lib. 1, p. 34-39: ''Sol 
hie noster nil aliud est quam una ex fixis, nobis major et clarior visa, 
quia, propior quam fix a. Pone terram stare ad latus, una semi-diamctro 
vim lactece, tunc hcsc via lactea apparebit circulus parvus, vet ellipsis par- 
va, tota declinans ad latus alterum; eritque simul uno intuitu conspicua, 
qucB nunc non potest nisi dimidia corispici quovis momcnto. Itaque fix' 
arum sphcera non tantum orhe stellarum, sed etiam circulo lactis versus 
nos deorsum est terminata.^^ 



SIDEREAL SYSTEMS. 89 

third oi'its length into two branches ; it is supposed that we 
are near this division, and nearer to the region of Sirius than 
to the constellation Aquila, almost in the middle of the stra- 
tum in the line of its thickness or minor axis. 

This position of our solar system, and the form of the whole 
discoidal stratum, have been inferred from sidereal scales, that 
is to say, from that method of counting the stars to which I 
have already alluded, and which is based upon the equidistant 
subdivision of the telescopic field of view. The relative depth 
of the stratum in all directions is measured by the greater or 
smaller number of stars appearing in each division. These 
divisions give the length of the ray of vision in the same man- 
ner as we measure the depth to which the plummet has been 
thrown, before it reaches the bottom, although in the case of 
a starry stratum there can not, correctly speaking, be any idea 
of depth, but merely of outer limits. In the direction of the 
longer axis, where the stars lie behind one another, the more 
remote ones appear closely crowded together, united, as it were, 
by a milky- white radiance or luminous vapor, and are perspec- 
tively grouped, encircling, as in a zone, the visible vault of 
heaven. This narrow and branched girdle, studded with ra- 
diant light, and here and there interrupted by dark spots, de- 
viates only by a few degrees from forming a perfect large cir- 
cle round the concave sphere of heaven, owing to our being 
near the center of the large starry cluster, and almost on the 
plane of the Milky Way. If our planetary system were far 
outside this cluster, the Milky Way would appear to tele- 
scopic vision as a ring, and at a still greater distance as a re- 
solvable discoidal nebula. 

Among the many self-luminous moving suns, erroneously 
called fixed stag's, which constitute our cosmical island, our 
own sun is the only one known by direct observation to be a 
central body in its relations to spherical agglomerations of 
matter directly depending upon and revolving round it, either 
in the form of planets, comets, or aerolite asteroids. As far 
as we have hitherto been able to investigate midtiple stars 
(double stars or suns), these bodies are not subject, with re- 
spect to relative motion and illumination, to the same planet- 
ary dependence that .characterizes our own solar system. Two 
or more self-luminous bodies, whose planets and moon, if such 
exist, have hitherto escaped our telescopic powers of vision, 
certainly revolve around one common center of gravity ; but 
this is in a portion of space which is probably occupied merely 
by unagglomerated matter or cosmical vapor, while in our sys- 



90 COSMOS. 

tern the center of gravity is often comprised within the inner- 
most limits of a visible central body. If, therefore, we regard 
the Sun and the Earth, or the Earth and the Moon, as double 
stars, and the whole of our planetary solar system as a multi- 
ple cluster of stars, the analogy thus suggested must be limit • 
ed to the universality of the laws of attraction in different sys- 
tems, being alike applicable to the independent processes of 
light and to the method of illumination. 

For the generalization of cosmical views, corresponding with 
the plan we have proposed to follow in giving a delineation of 
nature or of the universe, the solar system to which the Earth 
belongs may be considered in a two-fold relation : first, with 
respect to the different classes of individually agglomerated 
matter, and the relative size, conformation, density, and dis- 
tance of the heavenly bodies of this system ; and, secondly, 
with reference to other portions of our starry cluster, and of 
the changes of position of its central body, the Sun. 

The solar system, that is to say, the variously-formed matter 
circling round the Sun, consists, according to the present state 
of our knowledge, of eleven 'primary j^lcmets* eighteen satel- 

* [Since the publication of Bavon Humboldt's work in 1845, several 
other planets have been discovered, making the number of those be- 
longing to our planetary system sixteen instead of eleven. Of these, 
Astrea, Hebe, Flora, and Iris are members of the remarkable group 
of astei'oids between Mars and Jupiter. Astrea and Hebe were dis- 
covered by Hencke at Driesen, the one in 1846 and the other in 1847 ; 
Flora and Iris were both discovered in 1847 by Mr. Hind, at the South 
Villa Observatory, Regent's Park. It would appear from the latest de- 
terminations of their elements, that the small planets have the following 
order with respect to mean distance from the Sun : Flora, Iris, Vesta, 
Hebe, Astrea, Juno, Ceres, Pallas. Of these, Flora has the shortest 
period (about 34 years). The planet Neptune, 'which, after having 
been predicted by several astronomers, was actually observed on the 
25th of September, 1846, is situated on the confines of our planetary 
system beyond Uranus. The discovery of this planet is not only highly 
interesting from the importance attached to it as a question of science^ 
but also from the evidence it affords of the care and unremitting labor 
evinced by modern astronomers in the investigatioji and comparison of 
the older calculations, and the ingenious application of the results thus 
obtained to the observation of new facts. The merit of having paved 
the way for the discovery of the planet Neptune is due to M. Bouvard. 
who, in his persevering and assiduous efforts to deduce the entire orbit 
of Uranus from observations made during the forty years that succeed- 
ed the discovery of that planet in 1781, found the results yielded by 
theory to be at variance with fact, in a degree that had no parallel in 
the history of astronomy. This startling discrepancy, which seemed 
only to gain additional weight from every attempt made by M. Bouvard 
to correct his calculations, led Leverrier, after a careful modification of 
the tables of Bouvard. to establish the proposition that there was " a 



PLANETARY SYSTEMS. 91 

iites or secondary planets, and myriads of comets, three of 
which, known as the "planetary comets," do not pass beyond 
the narrow limits of the orbits described by the principal 
planets. We may, with no inconsiderable degree of proba- 
bility, include within the domain of our Sun, in the immedi- 
ate sphere of its central force, a rotating ring of vaporous mat- 
ter, lying probably between the orbits of Venus and Mars, but 
certainly beyond that of the Earth,=^ which appears to us in 

formal incompatibility between the observed motions of Uranus and 
the hypothesis that he was acted on ojily by the Sun and known plan- 
ets, according to the law of universal gravitation." Pursuing this idea, 
Leverrier arrived at the conclusion that the disturbing cause must be a 
planet, and, finally, after an amount of labor that seems perfectly over- 
whelming, he, on the 31st of August, 1846, laid before the French In- 
stitute a paper, in w^hich he indicated the exact spot in the heavens 
where this new planetaiy body would be found, giving the following 
data for its various elements : mean distance from the Sun, 36-154 times 
that of the Earth; period of revolution, 217'387 years; mean long., 
Jan. 1st, 1847, 318^ 47'; mass, ^ 3V0 ^h 5 heliocentric long., Jan. 1st, 
1847, 326° 32'. Essential difficulties still intervened, however, and as 
the remoteness of the planet rendered it improbable that its disk would 
be discernible by any telescopic instrument, no other means remained 
for detecting the suspected body but its planetary motion, which could 
only be ascertained by mapping, after every observation, the quarter 
of the heavens scanned, and by a comparison of the various maps. 
Fortunately for the verification of Leverrier's predictions, Dr. Bremiker 
had just completed a map of the precise region in which it was expect- 
ed the new planet would appear, this being one of a series of maps 
made for the Academy of Berlin, of the small stars along the entire zo- 
diac. By means of this valuable assistance, Dr. Galle, of the Berlin 
Observatory, was led, on the 25th of September, 184G, by the discov- 
ery of a star of the eighth magnitude, not recorded in Dr. Bremiker's 
map, to make the first observation of the planet predicted by Leverrier. 
By a singular coincidence, Mr. Adams, of Cambridge, had predicted 
the appearance of the planet simultaneously with M. Leverrier; but 
by the concurrence of several circumstances much to be regretted, the 
world at large were not made acquainted with Mr. Adams's valuable 
discovery until subsequently to the period at which Leverrier published 
his observations. As the data of Leverrier and Adams stand at present, 
there is a discrepancy between the predicted and the true distance, and 
in some other elements of the planet ; it remains, therefore, for these 
or future astronomers to reconcile theory with fact, or perhaps, as in 
the case of Uranus, to make the new planet the means of lea-ding to yet 
greater discoveries. It would appear from the most recent observations, 
that the mass of Neptune, instead of being, as at first stated, ^ jq o^h, is 
only about _^__th that of the Sun, while its periodic time is now given 
w^ith a greater probability at 166 years, and its mean distance from the 
Sun nearly 30. The planet appears to have a ring, but as yet no ac- 
curate observations have been inade regarding its system of satellites. 
See Trans. Astron. Soc, and The Planai Neptune, 1848, by J . P. Nicholl. 1 
— Tr. 

* " If there should be molecules in the zones diffused by the atmo» 



92 COSMOS 

a pyramidal form, and is known as the Zodiacal Light ; and 
a host of very small asteroids, whose orbits either intersect, or 
very nearly approach, that of our earth, and which present us 
with the phenomena of aerolites and falling or shooting stars. 
When we consider the complication of variously-formed bodies 
which revolve round the Sun in orbits of such dissimilar ec- 
centricity — although we may not be disposed, with the im- 
mortal author of the Mecanique Celeste, to regard the larger 
number of comets as nebulous stars, passing from one central 
system to another,* we yet can not fail to acknowledge that 
the planetary system, especially so called (that is, the group 
of heavenly bodies which, together with their satellites, re- 
volve with but slightly eccentric orbits round the Sun), con- 
stitutes but a small portion of the whole system with respect 
to individual numbers, if not to mass. 

It has been proposed to consider the telescopic planets, Ves- 
ta, Juno, Ceres, and Pallas, with their more closely intersect- 
ing, inclined, and eccentric orbits, as a zone of separation, or 
as a middle group in space ; and if this view be adopted, we 
shall discover that the interior planetary group (consisting of 
Mercury, Venus, the Earth, and Mars) presents several very 
striking contrasts! when compared with the exterior group, 
comprising Jupiter, Saturn, and Uranus. The planets near- 
est the Sun, and consequently included in the inner group, are 
of more moderate size, denser, rotate more slowly and with 
nearly equal velocity (their periods of revolution being almost 
all about 24 hours), are less compressed at the poles, and, with 
the exception of one, are without satellites. The exterior 
planets, which are further removed from the Sun, are very 
considerably larger, have a density five times less, more than 
twice as great a velocity in the period of their rotation round 
their axes, are more compressed at the poles, and if six satel- 
lites may be ascribed to Uranus, have a quantitative prepon- 
derance in the number of their attendant moons, which is as 
seventeen to one. 

phere of the Sun of too volatile a nature either to combine Avith one 
another or with the planets, we must suppose that they would, in cir- 
cling round that luminary, present all the appearances of zodiacal light, 
without opposing any appreciable resistance to the different bodies com- 
posing the planetary system, either owing to their extreme rarity, oi* 
to the similarity existing between their motion and that of the planets 
with which they come in contact." — Laplace, Expos, du Syst. du MondAi 
(ed. 5), p. 415. 

* Laplace, Exp. du Syst. du Monde, p. 396, 414. 

t Littrow, Astronomic, l8iJ5, bd. xi., § 107. Madler, Astron., 1841, 
$ 212. Laplace, Exp. d*. Syst. du Monde, p. 210. 



PLANETARY SYSTEMS. 93 

Such general considerations regarding certain characteristic 
properties appertaining to whole groups, can not, however, be 
applied with equal justice to the individual planets of every 
group, nor to the relations between the distances of the revolv- 
nig planets from the central body, and their absolute size, 
density, period of rotation, eccentricity, and the inclination of 
their orbits and the axes. We know as yet of no inherent ne- 
cessity, no mechanical natural law, similar to the one which 
teaches us that the squares of the periodic times are propor- 
tional to the cubes of the major axes, by which the above- 
named six elements of the planetary bodies and the form of 
their orbit are made dependent either on one another, or on 
their mean distance from the Sun. Mars is smaller than the 
Earth and Venus, although further removed from the Sun 
than these last-named planets, approaching most nearly in size 
to Mercury, the nearest planet to the Sun. Saturn is smaller 
than Jupiter, and yet much larger than Uranus. The zone 
of the telescopic planets, which have so inconsiderable a vol 
ume, immediately precede Jupiter (the greatest in size of an) 
of the planetary bodies), if we consider them with regard to 
distance from the Sun ; and yet the disks of these small aster- 
oids, which scarcely admit of measurement, have an areal sur- 
face not much more than half that of France, Madagascar, or 
Borneo. However striking may be the extremely small dens- 
ity of all the colossal planets, which are furthest removed from 
the Sun, we are yet unable in this respect to recognize any 
regular succession.* Uranus appears to be denser than Sat- 
urn, even if we adopt the smaller mass, -34 o o 5> assumed by 
Lament ; and, notwithstanding the inconsiderable difference 
of density observed in the mnermost planetary group,t we find 
both Venus and Mars less dense than the Earth, which lies 
between them. The time of rotation certainly diminishes 
with increasing solar distance, but yet it is greater in Mars 
than in the Earth, and in Saturn than in Jupiter. The el- 

* See Kepler, on the increasing density and volume of the planets in 
proportion with their increase of distance from the Sun, which is de- 
scribed as the densest of all the heavenly bodies ; in the Epitome As- 
iron. Copern. in vii. libros digesta, 1618-1622, p. 420. Leibnitz also in- 
clined to the opinions of Kepler and Otto von Guericke, that the plan- 
ets increase in volume in proportion to their increase of distance from 
the Sun. See his letter to the Magdeburg Burgomaster (Mayence, 
1671), in Leibnitz, Deutschen Schriften, herausg. von Guhrauer, th. i., 
I 264. 

t On the arrangement of masses, see Encke, in Schum., Astr. Nachr. 
1843 Nr. 488, $ 114. 



94 COSMOS. 

liptic orbits of Juno, Pallas, and Mercury have the greatest 
degree of eccentricity, and Mars and Venus, which immedi- 
ately follow each other, have the least. Mercury and Venus 
exhibit the same contrasts that may be observed in the four 
smaller planets, or asteroids, whose paths are so closely inter- 
woven. 

The eccentricities of Juno and Pallas are very nearly iden- 
tical, and are each three times as great as those of Ceres and 
Vesta. The same may be said of the inclination of the orbits 
of the planets toward the plane of projection of the ecliptic, or 
in the position of their axes of rotation with relation to their 
orbits, a position on which the relations of chmate, seasons of 
the year, and length of the days depend, more than on eccen- 
tricity. Those planets that have the most elongated elliptic 
orbits, as Juno, Pallas, and Mercury, have also, although not 
to the same degree, their orbits most strongly inclined toward 
the ecliptic. Pallas has a comet-like inclination nearly twen- 
ty-six times greater than that of Jupiter, while in the little 
planet Vesta, which is so near Pallas, the angle of inclination 
scarcely by six times exceeds that of Jupiter. An equally ir- 
regular succession is observed in the position of the axes of 
the few planets (four or five) whose planes of rotation we 
know with any degree of certainty. It would appear from 
the position of the satellites of Uranus, two of which, the sec- 
ond and fourth, have been recently observed with certainty, 
that the axis of this, the outermost of all the planets, is scarce- 
ly incHned as much as 11° toward the plane of its orbit, while 
Saturn is placed between this planet, whose axis almost coin- 
cides with the plane of its orbit, and J upiter, whose axis of 
rotation is nearly perpendicular to it. 

In this enumeration of the forms which compose the world 
in space, we have delineated them as possessing an actual ex- 
istence, and not as objects of intellectual contemplation, or as 
mere links of a mental and causal chain of connection. The 
planetary system, in its relations of absolute size and relative 
position of the axes, density, time of rotation, and different de- 
gress of eccentricity of the orbits, does not appear to offer to 
our apprehension any stronger evidence of a natural necessity 
than the proportion observed in the distribution of land and 
water on the Earth, the configuration of continents, or the 
height of mountain chains. In these respects we can discover 
no common law in the regions of space or in the inequalities 
of the earth's crust. They are facts in nature that have 
arisen firgm the conflict of manifold forces acting under un- 



PLANET All V SYriTEMS. 95 

known conditions, although nian considers as accidental what- 
ever he is unable to explain in the planetary formation on pure- 
ly genetic principles. If the planets have been formed out of 
separate rings of vaporous matter revolving round the Sun, 
we may conjecture that the different thickness, unequal dens- 
ity, temperature, and electro-magnetic tension of these rings 
may have given occasion to the most various agglomerations 
of matter, in the same manner as the amount of tangential 
velocity and small variations in its direction have produced so 
great a difference in the forms and inclinations of the elliptic 
orbits. Attractions of mass and laws of gravitation have no 
doubt exercised an influence here, no less than in the geog- 
nostic relations of the elevations of continents ; but we are un- 
able from present forms to draw any conclusions regarding the 
series of conditions through which they have passed. Even 
the so-called law of the distances of the planets from the Sun, 
the law of progression (which led Kepler to conjecture the ex- 
istence of a planet supplying the link that was wanting in the 
chain of connection between Mars and Jupiter), has been found 
numerically inexact for the distances between Mercury, Venus, 
and the Earth, and at variance with the conception of a series, 
owing to the necessity for a supposition in the case of the first 
member. 

The hitherto discovered principal planets that revolve round 
our Sun are attended certainly by fourteen, and probably by 
eighteen secondary planets (moons or satellites). The princi- 
pal planets are, therefore, themselves the central bodies of sub- 
ordinate systems. We seem to recognize in the fabric of the 
universe the same process of arrangement so frequently ex- 
hibited in the development of organic life, where we find in 
the manifold combinations of groups of plants or animals the 
same typical form repeated in the suhoi'dinate classes. The 
secondary planets or satellites are more frequent in the extern- 
al region of" the planetary system, lying beyond the intersect- 
ing orbits of the smaller planets or asteroids ; in the inner re- 
gion none of the planets are attended by satellites, with the 
exception of the Earth, whose moon is relatively of great mag- 
nitude, since its diameter is equal to a fourth of that of the 
Earth, while the diameter of the largest of all known second- 
ary planets — the sixth satellite of Saturn — is probably about 
one seventeenth, and the largest of Jupiter's moons, the third, 
only about one twenty-sixth part that of the primary planet 
or central body. The planets which are attended by the 
largest number of satelhtes are most remote from the Sun, 



96 COSMOS. 

and are at the same time the largest, most compressed at the 
poles, and the least dense. According to the most recent 
measurements of Madler, Uranus has a greater planetary 
compression than any other of the planets, viz., -g-.^^d. In our 
Earth and her moon, whose mean distance from one another 
amounts to 207,200 miles, we find that the difierences of 
mass* and diameter between the two are much less consider- 
able than are usually observed to exist between the principal 
planets and their attendant satellites, or between bodies of 
difi'erent orders in the solar system. While the density of the 
Moon is five ninths less than that of the Earth, it would ap- 
pear, if we may sufficiently depend upon the determinations 
of their magnitudes and masses, that the second of Jupiter's 
moons is actually denser than that great planet itself. Among 
the fourteen satelHtes that have been investigated with any 
degree of certainty, the system of the seven satellites of Saturn 
presents an instance of the greatest possible contrast, both in 
absolute magnitude and in distance from the central body. 
The sixth of these satellites is probably not much smaller than 
Mars, while our moon has a diameter which does not amount 
to more than half that of the latter planet. With respect to 
volume, the two outer, the sixth and seventh of Saturn's satel- 
lites, approach the nearest to the third and brightest of Jupi- 
ter's moons. The two innermost of these satellites belong 
perhaps, together with the remote moons of Uranus, to the 
smallest cosmical bodies of our solar system, being only made 
visible under favorable circumstances by the most powerful 
instruments. They were first discovered by the ibrty-foot 
telescope of William Herschel in 1789, and were seen again 
by John Herschel at the Cape of Good Hope, by Vice at Rome, 
and by Lamont at Munich. Determinations of the true di- 
ameter of satellites, made by the measurement of the apparent 
size of their small disks, are subjected to many optical diffi- 
culties ; but numerical astronomy, whose task it is to prede- 
termine by calculation the motions of the heavenly bodies as 
they will appear when viewed from the Earth, is directed al- 

* If, according to Burckhardt's determination, the Moon's radius be 
0.2725 and its volume _-J;_-^th, its density will be 0*5596, or nearly five 
ninths. Compare, also, Willi. Beer und H. Madler, der Mond, § 2, 
10, and Madler, Ast., § 157. The material contents of the Moon are, 
according to Hansen, nearly ^^th (and according to Madler ^i._-th) 
that of the Earth, and its mass equal to g^.^^ d that of the Earth. lu 
the largest of Jupiter's moons, the third, the relations of volume to the 
central body are -r^^..-„th, and of mass --A_._th. On the polar flatten- 

, *' 1 .■> .< 7 1 1 J U * 

mg ot Uranus, see Schum., Aalron. Nachr., 1844, No. 493. 



PLANETARY SYSTEMS. 97 

most, exclusively to motion and mass, and but little to volume. 
The absolute distance of a satellite from its central body is 
greatest in the case of the outermost or seventh satellite of 
Saturn, its distance from the body round vv^hich it revolves 
amounting to more than two millions of miles, or ten times as 
great a distance as that of our moon from the Earth. In the 
case of Jupiter we find that the outermost or fourth attendant 
moon is only 1,040,000 miles from that planet, while the dis- 
tance between Uranus and its sixth satellite (if the latter real- 
ly exist) amounts to as much as 1,360,000 miles. If we com- 
pare, in each of these subordinate systems, the volume of the 
main planet with the distance of the orbit of its most remote 
satellite, we discover the existence of entirely new numerical 
relations. The distances of the outermost satellites of Uranus, 
Saturn, and Jupiter are, when expressed in semi-diameters 
of the main planets, as 91, 64, and 27. The outermost satel- 
lite of Saturn appears, therefore, to be removed only about 
one fifteenth further from the center of that planet than our 
moon is from the Earth. The first or innermost of Saturn's 
satellites is nearer to its central body than any other of the 
secondary planets, and presents, moreover, the only instance 
of a period of revolution of less than twenty-four hours. Its 
distance from the center of Saturn may, according to Madler 
and Wilhelm Beer, be expressed as 2-47 semi-diameters of that 
planet, or as 80,088 miles. Its distance from the surface of 
the main planet is therefore 47,480 miles, and from the outer- 
most edge of the ring only 4916 miles. The traveler may 
form to himself an estimate of the smallness of this amount 
by remembering the statement of an enterprising navigator, 
Captain Beechey, that he had in three years passed over 72,800 
miles. If, instead of absolute distances, we take the semi-di- 
ameters of the principal planets, we shall find that even the 
first or nearest of the moons of Jupiter (which is 26,000 miles 
further removed from the center of that planet than our moon 
is from that of the Earth) is only six semi-diameters of Jupiter 
from its center, while our moon is removed from us fully 60 ^d 
semi-diameters of the Earth. 

In the subordinate systems of satellites, we find that the 
same laws of gravitation which regulate the revolutions of the 
principal planets round the Sun hkewise govern the mutual 
relations existing between these planets among one another 
and with reference to their attendant satellites. The twelve 
moons of Saturn, Jupiter, and the Earth all move like the 
primary planets from west to east, and in elliptic orbits, do- 

Vol. I.— E 



98 COSMOS. 

viatiiig but little from circles. It is only in the case of ouf 
moon, and perhaps in that of the first and innermost of tha 
satellites of Saturn (0'068), that we discover an eccentricity 
greater than that of Jupiter ; according to the very exact ob- 
servations of Bessel, the eccentricity of the sixth of Saturn's 
satellites (0'029) exceeds that of the Earth. On the extremes! 
limits of the planetary system, vv^here, at a distance nineteen 
times greater than that of our Earth, the centripetal force of 
the Sun is greatly diminished, the satellites of Uranus (which 
have certainly been but imperfectly investigated) exhibit tht 
most striking contrasts from the facts observed with regard t(? 
other secondary planets. Instead, as in all other satellites, of 
having their orbits but slightly inclined toward the ecliptic 
and (not excepting even Saturn's ring, which may be regard- 
ed as a fusion of agglomerated satellites) moving from west tc 
east, the satellites of Uranus are almost perpendicular to the 
ecliptic, and move retrogressively from east to west, as Sir 
John Herschel has proved by observations continued during 
many years If the primary and secondary planets have been 
formed by the condensation of rotating rings of solar and plan- 
etary atmospheric vapor, there must have existed singular 
causes of retardation or impediment in the vaporous rings re- 
volving round Uranus, by which, under relations with which 
we are unacquainted, the revolution of the second and fourth 
of its satellites was made to assume a direction opposite to that 
of the rotation of the central planet. 

It seems highly probable that the period of rotation of all 
secondary planets is equal to that of their revolution round 
the main planet, and therefore that they always present to 
the latter the same side. Inequalities, occasioned by slight 
variations in the revolution, give rise -to fluctuations of from 
6'^ to 8*^, or to an apparent libration in longitude as well as 
in latitude. Thus, in the case of our moon, we sometimes 
observe more than the half of its surface, the eastern and 
northern edges being more visible at one time, and tlie west- 
ern or southern at another. By means of this libration* we 
ave enabled to see the annular mountain Malapert (which oc- 
casionally conceals the Moon's south pole), the arctic land- 
scape round the crater of Gioja, and the largf gray plane near 
Endymion, which exceeds in superficial extent the Mare Va- 
pormn. Three sevenths of the Moon's surface arc entirelj 

* Beer and Madler, op. cit., $ 185, s. 208, and *;j 347, s 33-J ; ,muI u 
their Phys. Kemiiniss der liimml. Korper, s. 4 uiiiJ 69. Tab. 1 ( l*hy&Jo 
al History of the Heavenly Bodies). 



COMETS. 9i> 

concealed from our observation, and must always remain so, 
unless new and unexpected disturbing causes come into play. 
These cosmical relations involuntarily remind us of nearly 
similar conditions in the intellectual world, where, in the do- 
main of deep research into the mysteries and the primeval 
creative forces of nature, there are regions similarly turned 
away from us, and apparently unattainable, of which only a 
narrow margin has revealed itself, for thousands of years, toi 
the human mind, appearing, from time to time, either glim- 
mering in true or delusive hght. We have hitherto consid- 
ered the primary planets, their satellites, and the concentric 
rings which belong to one, at least, of the outermost planets, 
as products of tangential force, and as closely connected to- 
gether by mutual attraction ; it therefore now only remains 
lor us to speak of the unnumbered host of comets which con- 
stitute a portion of the cosmical bodies revolving in independ- 
ent orbits round the Sun. If we assume an equable distribu- 
tion of their orbits, and the limits of their perihelia, or greatest 
proximities to the Sun, and the possibility of their remaining 
invisible to the inhabitants of the Earth, and base our esti- 
mates on the rules of the calculus of probabilities, we shall 
obtain as the result an amount of myriads perfectly astonish- 
ing. Kepler, with his usual animation of expression, said that 
there were more comets in the regions of space than fishes in 
the depths of the ocean. As yet, however, there are scarcely 
one hundred and fifty whose paths have been calculated, if 
we may assume at six or seven hundred the number of comets 
whose appearance and passage through known constellations 
have been ascertained by more or less precise observations. 
While the so-called classical nations of the West, the Greeks 
and Romans, although they may occasionally have indicated 
the position in which a comet first appeared, never afford any 
information regarding its apparent path, the copious literature 
of the Chinese (who observed nature carefully, and recorded 
with accuracy what they saw) contains circumstantial notices 
of the constellations through which each comet was observed 
to pass. These notices go back to more than five hundred 
years before the Christian era, and many of them are still 
found to be of value in astronomical observations. =^ 

* The first comets of whose orbits we have any knowledge, and 
which were calculated from Chinese observations, are those of 240 (un- 
der Gordian III.), 539 (under Justinian), 56-5, 568, 574, 837, 1337, and 
1385. See John Russell Hind, in Schiini., Astron. Nachr., 1843, No. 498. 
While ihe comet of 837 (which, a^cordin^ to Du Sejour, continued dur- 



100 COSMOS. 

Although comets have a smaller mass than anj^ other oos- 
mical bodies — being, according to our present knowledge, prob- 
ably not equal to joVo^h part of the Earth's mass — yet they 
occupy the largest space, as their tails in several instances ex- 
tend over many millions of miles. The cone of luminous va- 
por which radiates from them has been found, in some cases 
(as in 1680 and 1811), to equal the length of the Earth's 
distance from the Sun, forming a line that intersects both the 
orbits of Venus and Mercury. It is even probable that the 
vapor of the tails of comets mingled with our atmosphere in 
the years 1819 and 1823. 

Comets exhibit such diversities of form, which appear rath 
er to appertain to the individual than the class, that a de- 
scription of one of these " wandering light-clouds," as they 
were already called by Xenophanes and Theon of Alexandria, 
cotemporaries of Pappus, can only be applied with caution to 
another. The faintest telescopic comets are generally devoid 
of visible tails, and resemble Herschel's nebulous stars. They 
appear like circular nebulae of faintly-glimmering vapor, with 
the light concentrated toward the middle. This is the most 
simple type ; but it can not, however, be regarded as rudi- 
mentary, since it might equally be the type of an older cos 
mical body, exhausted by exhalation. In the larger comets 
we may distinguish both the so-called "head" or "nucleus," 
and the single or multiple tail, which is characteristically de 
nominated by the Chinese astronomers " the brush" [sui). 
The nucleus generally presents no definite outline, although, 
in a few rare cases, it appears like a star of the first or second 
magnitude, and has even been seen in bright sunshine ;^ as, 

ing twenty-four hours within a distance of 2,000,000 miles from the 
Earth) terrified Louis I. of France to that degree that he busied him 
self in building churches and founding monastic establishments, in the 
hope of appeasing the evils threatened by its appearance, the Chinese 
astronomers made observations on the path of this cosmical body, whose 
tail extended over a space of 60°, appearing sometimes single and 
sometimes multiple. The first comet that has been calculated solely 
from European observations was that of 1456, known as Halley's cor.Ti- 
et, from the belief long, but erroneously, entertained that the period 
when it was first observed by that astronomer was its first and only 
well-attested appearance. See Arago, in the Annuaire, 1836, p. 204, 
and Laugier, Comptes Rendus des Stances de VAcad., 1843, t. xvi., 
1006. 

* Arago, Annuaire, 1832, p. 209, 211. The phenomenon of the tail 
of a comet being visible in bright sunshine, which is recorded of the 
comet of 1402, occurred again in the case of the large comet of 1843, 
whose nucleus and tail were seen in North America on the 28th of Feb- 
raary (according to the testimony of J. G. Clarke, of Portland, state of 



COMETS. 101 

lor instance, in the large comets of 1402, 1532, 1577, 1744, 
and 1843. This latter circumstance indicates, in particular 
individuals, a denser mass, capable of reflecting Ught with 
greater intensity. Even in Herschel's large telescope, only 
two comets, that discovered in Sicily in 1807, and the splen- 
did one of 1811, exhibited well-defined disks ;* the one at an 
angle of 1", and the other at 0""77, whence the true diame- 
ters are assumed to be 536 and 428 miles. The diameters 
of the less well-defined nuclei of the comets of 1798 and 1805 
did not appear to exceed 24 or 28 miles. 

In several comets that have been investigated with great 
care, especially in the above-named one of 1811, which con- 
tinued visible for so long a period, the nucleus and its nebu- 
lous envelope were entirely separated from the tail by a darker 
space. The intensity of light in the nucleus of comets does 
not augment toward the center in any uniform degree, bright- 
ly shining zones being in many cases separated by concentric 
nebulous envelopes. The tails sometimes appear single, some- 
times, although more rarely, double ; and in the comets of- 
1807 and 1843 the branches were of difierent leno^ths ; in 
one instance (1744) the tail had six branches, the whole 
forming an angle of 60^. The tails have been sometimes 
straight, sometimes curved, either toward both sides, or to- 
ward the side appearing to us as the exterior (as in 1811), or 
convex toward the direction in which the comet is moving 
(as in that of 1618) ; and sometimes the tail has even ap- 
peared like a flame in motion. The tails are always turned 
away from the sun, so that their line of prolongation passes 
through its center ; a fact which, according to Edward Biot, 
was noticed by the Chinese astronomers as early as 837, but 
was first generally made known in Europe by Fracastoro and 
Peter Apian in the sixteenth century. These emanations 
may be regarded as conoidal envelopes of greater or less thick- 

Maiue), between 1 and 3 o'clock in the afternoon.* The distance of 
the very dense nucleus from the sun's light admitted of being measured 
with much exactness. The nucleus and tail a{)peared like a very pure 
white cloud, a darker space intervemng between the tail and the nu- 
cleus. {Amer- Journ. of Science, vol. xlv., No. 1, p. 229.) 

* Phil. Trans, for 1808, Part ii., p. 155, and for 1812, Part i., p. 118 
The diameters found by Herschel for the nuclei were 538 <inJ 428 En 
glish miles. For the magnitudes of the comets of 1798 and ISOJ. st;e 
Arago, Annnaire, 1832, p. 203. 

a [The translator was at New Bedford, Massachusetts, U. S., on the 2Sth Februa- 
ry, 1843, and distinctly saw the comet, between 1 and 2 in the afternoon. The skj 
at the time was intensely blue, and the sun shining with a dazzling brightnoos un- 
known in European climates.] — Tr 



102 * COSMOS. 

ness, and, considered in this manner, they furnish a simple 
explanation of many of the remarkable optical phenomena al- 
ready spoken of. 

Comets are not only characteristically different in form, 
some being entirely without a visible tail, while others have 
a tail of immense length (as in the instance of the comet of 
1618, whose tail measured 104°), but we also see the same 
comets undergoing successive and rapidly-changing processes 
of configuration. These variations of form have been most 
accurately and admirably described in the comet of 1744, by 
Hensius, at St. Petersburg, and in Halley's comet, on its last 
reappearance in 1835, by Bessel, at Konigsberg. A more or 
less well-defined tuft of rays emanated from that part of the 
nucleus which was turned toward the Sun ; and the rays be- 
ing bent backward, formed a part of the tail. The nucleus 
of Halley's comet, with its emanations, presented the appear- 
ance of a burning rocket, the end of which was turned side- 
ways by the force of the wind. The rays issuing from the 
head were seen by Arago and myself, at the Observatory at 
Paris, to assume very different forms on successive nights.* 
The great Konigsberg astronomer concluded from many meas- 
urements, and from theoretical considerations, " that the cone 
of light issuing from the comet deviated considerably both to 
the right and the left of the true direction of the Sun, but 
that it always returned to that direction, and passed over to 
the opposite side, so that both the cone of light and the body 
of the comet from whence it emanated experienced a rotatory, 
or, rather, a vibratory motion in the plane of the orbit." He 
finds that " the attractive force exercised by the Sun on heavy 
bodies is inadequate to explain such vibrations, and is of opin- 
ion that they indicate a polar force, which turns one semi-di- 
ameter of the comet toward the Sun, and strives to turn the 
opposite side away from that luminary. The magnetic polar- 
ity possessed by the Earth may present some analogy to this ; 
and, should the Sun have an opposite polarity, an influence 
might be manifested, resulting in the precession of the equi- 
noxes." This is not the place to enter more fully upon the 
grounds on which explanations of this subject have been bas- 
ed ; but observations so remarkable,! and views of so exalted 

* Arago, Des Changemenis physiques de la Comete de Halley du 15- 
23 Oct., 1835. Annnaire, 1836, p. 218, 221. The ordinary direction 
of the emanations was noticed even in Nero's time. " Comce radios sO' 
lis effugiunt.^^ — Seneca, Nat. Qucest., vii., 20. 

t Bessel, in Schumacher, Astr. Nachr., 1836, No. 300-302, s. 188, 192, 



COMETS. 103 

I character, regarding the most wonderful class of the cosmic- 
al bodies belonging to our solar system, ought not to be en- 
tirely passed over in this sketch of a general picture of nature. 

Although, as a rule, the tails of comets increase in magni- 
tude and brilliancy in the vicinity of the sun, and are directed 
away from that central body, yet the comet of 1823 ofiered 
the remarkable example of two tails, one of which was turned 
toward the sun, and the other away from it, forming with 
each other an angle of 160°. Modifications of polarity and 
the unequal manner of its distribution, and of the direction in 
which it is conducted, may in this rare instance have occa- 
sioned a double, unchecked, continuous emanation of nebulous 
matter,* 

Aristotle, in his Natural Philosophy^ makes these emana- 
tions the means of bringing the phenomena of comets into a 
singular connection with the existence of the Milky Way. 
According to his views, the innumerable quantity of stars 
which compose this starry zone give out a self-luminous, in- 
candescent matter. The nebulous belt which separates the 
different portions of the vault of heaven was therefore regard- 
ed by the Stagirite as a large comet, the substance of which 
was incessantly being renewed.! 

197, 200, 20-2, und 230. Also in Schumacher, Jahrb., 1837, s. 149, 168. 
William Herschel, in his observations on the beautiful comet of 1811, 
believed that he had discovered evidences of the rotation of the nucleus 
and tail {Phil. Trans, for 1812, Part i., p. 140). Duulop, at Paramat- 
ta, thought the same with reference to the third comet of 1825. 

* Bessel, in Astr. Nachr., 1836, No. 302, s. 231. Schum., Jahrb., 1837. 
s. 175. See, also, Lehmaun, Ueber Cometenschiceife (On the Tails of 
Comets), in Bode, Astron. Jahrb. fur 1826, s. 168. 

t Aristot., Meteor., i., 8, 11-14, und 19-21 (ed. Ideler, t. i., p. 32-34). 
Biese, Phil, des Aristoteles, bd. ii., s. 86. Since Aristotle exercised so 
great an influence throughout the whole of the Middle Ages, it is very 
much to be regretted that he was so averse to those grander views of 
the elder Pythagoreans, which inculcated ideas so nearly approxima- 
ting to truth respecting the structure of the universe. He asserts that 
comets are transitory meteors ^belonging to our atmosphere in the very 
book in which he cites the opinion of the Pythagorean school, accord- 
ing to which these cosmical bodies are supposed to be planets having 
long periods of revolution. (Aristot., i., 6, 2.) This Pythagorean doc- 
trine, which, according to the testimony of ApoUonius Myndius, was 
still more ancient, having oingiuated with the Chaldeans, ])a3scd over 
to the Romans, who in this instance, as was their usual practice, were 
merely the copiers of others. The Myndian philosopher describes the 
path of comets as directed toward the upper and remote regions of 
heaven. Hence Seneca says, in his Nat. Qucest., vii., 17: ^^ Comeles 
pon est species falsa, sed propHum sidus sicnt solis et lunce : altiora mnn- 
di secat et tunc demum apparct quum in imum cwrsum stii venil;^' and 
'Again (at vii., 27), " Cometes ceternos esse et sortis ejvsdem, cvjns ctr.tera 



104 C0SM09. 

The occultat.ion of the fixed stars by the nucleus of a com 
et, or by its innermost vaporous envelopes, might throw some 
light on the physical character of these wonderful bodies ; but 
we are unfortunately deficient in observations by which we 
may be assured* that the occultation was perfectly central ; 
for, as it has already been observed, the parts of the envelope 
contiguous to the nucleus are alternately composed of layers 
of dense or very attenuated vapor. On the other hand, the 
carefully conducted measurements of Bessel prove, beyond all 
doubt, that on the 29th of September, 1835, the light of a 
star of the tenth magnitude, which was then at a distance of 
7"-78 from the central point of the head of Halley's comet, 
passed through very dense nebulous matter, without experi- 
encing any deflection during its passage.! If such an absence 
of refracting power must be ascribed to the nucleus of a com- 
et, tve can scarcely regard the matter composing comets as a 
gaseous fluid. The question here arises whether this absence 
of refracting power may not be owing to the extreme tenuity 
of the fluid ; or does the comet consist of separated particles 
constituting a cosmical stratum of clouds, which, like the 
clouds of our atmosphere, that exercise no influence on the 

{sidera), etiamsi faciem illis non habent similemJ''' Pliny (ii., 25) also re- 
fers to Apollonius Myndius, when he says, "-Sunt qui et kcBC sidera per- 
petua esse credant sitoque amhitu ire, sed non nisi relicta a sole cerniy 

* Olbers, in Asir. Nachr., 1828, s. 157, 184. Arago, De la Constitu- 
tion physique des C o metes ; Annuaire de 1832, p. 203, 208. The an- 
cients were struck by the phenomenon that it was possible to see 
through comets as throusrh a flame. The earliest evidence to be met 
with of stars having been seen throngh comets is that of Democntus 
(Aristot., Metear., i., 6, 11), and the statement leads Aristotle to make 
the not miimportant remark, that he himself had observed the occulta- 
tion of one of the stars of Gemini by Jupiter. Seneca only speaks de- 
cidedly of the transparence of the tail of comets. " We may see," says 
he, "stars through a comet as through a cloud (Nat. Qucest., vii., 18); 
but we can only see through the rays of tlie tail, and not through the 
body of the comet itself: non in ea parte qua sidns ipsum est spissi et 
:^olidi ignis, sed qua varus splendor occurrit et in crines dispergitur. Per 
intervalla ignium, non per ipsos, vides" (vii., 26). The last remark is 
unnecessary, since, as Galileo observed in the Saggialore {Lettera a 
Monsignor CesaHni, 1G19), we can certainly see through a flame when 
it is not of too great a thickness. 

t Bessel, in the Astron. Nachr., 1836, No. 301, s. 204, 206. Struve, 
in Recueil des Mim. de V Acad, dc St. Petcrsh., 1836, p. 140, 143, and 
Astr. Nachr., 1836, No. 303, s. 238, writes as follows: "At Dorpat the 
star was in conjunction only 2"*2 from the Imghtest point of the comet. 
The star remained continually visible, and its hght was not perceptibly 
diminished, while the nucleus of the comet tfeemed to be almost extin 
guished before the radiance of the small star of the ninth or tenth mag 
nitude." 



COMETS. 105 

zenith distance of the stars, does not affect the ray of light 
passing through it ? In the passage of a comet over a star, a 
more or less considerable diminution of light has often been 
observed ; but this has been justly ascribed to the brightness 
of the ground from which the star seems to stand forth during 
the passage of the comet. 

The most important and decisive observations that we pos- 
sess on the nature and the light of comets are due to Arago's 
polarization experiments. His polariscope instructs us re- 
garding the physical constitution of thfe Sun and comets, indi- 
cating whether a ray that reaches us from a distance of many 
millions of miles transmits light directly or by reflection ; and 
if the former, whether the source of light is a sofld, a liquid, 
or a gaseous body. His apparatus was used at the Paris Ob- 
servatory in examining the hght of Capella and that of the 
great comet of 1819. The latter shov/ed polarized, and there- 
fore reflected hght, while the fixed star, as was to be expect- 
ed, appeared to be a self-luminous sun.* The existence of 
polarized cometary light announced itself not only by the in- 
equality of the images, but was proved with greater certainty 
on the reappearance of Halley's comet, in the year 1835, by 
the more striking contrast of the complementary colors, de- 
duced from the laws of chromatic polarization discovered by 
Arago in 1811. These beautiful experiments still leave it 
undecided whether, in addition to this reflected solar light, 
comets may not have light of their own. Even in the case 
of the planets, as. for instance, in Venus, an evolution of ui- 
dependent light seems very probable. 

The variable intensity of light in comets can not always be 

* On the 3d of July, 1819, Arago made the first attempt to analyze 
the light of comets by polarization, on the evening of the sudden ap 
pearance of the great comet. I was present at the Paris Observatory, 
and was fully convinced, as were also Matthieu and the late Bouvard, 
of the dissimilarity in the intensity of the light seen in the polariscope, 
when the instrument received cometary light. When it received light 
from Capella, which was near the comet, and at an equal altitude, the 
images were of equal intensity. On the reappearance of Halley's com- 
et in 1835, the instrument was altered so as to give, according to Ara- 
go's chromatic polarization, two images of complementary colors (gieen 
and red). {Annates de Chimie, t. xiii., p. 108; Annuaire, 1832, p. 216.) 
" We must conclude from these observations," says Arago, " that the 
cometary light was not entirely composed of rays having the properties 
of direct light, there being light which was reflected specularly or po- 
larized, that is, coming from the sun. It can not be stated with abso- 
lute certainty that comets shine only with borrowed light, for bodies,, 
in becoming self-luminous, do not, on that account, lose the power of 
reflecting foreign light." 

E 2 



106 COSMOS. 

explained by tlie position of their orbits and their distance from 
the Sun. It would seem to indicate, in some individuals, the 
existence of an inherent process of condensation, and an in- 
creased or diminished capacity of reflecting borrowed light. 
In the comet of 1618, and in that which has a period of three 
years, it was observed first by Hevelius that the nucleus of 
the comet diminished at its perihelion and enlarged at its 
aphelion, a fact which, after remaining long unheeded, was 
again noticed by the talented astronomer Valz at Nismes. 
The regularity of the change of volume, according to the dif- 
ferent degrees of distance from the Sun, appears very striking. 
The physical explanation of the phenomenon can not, howev- 
er, be sought in the condensed layers of cosmical vapor occur- 
ring in the vicinity of the Sun, since it is difficult to imagine 
the nebulous envelope of the nucleus of the comet to be vesic- 
ular and impervious to the ether.* 

The dissimilar eccentricity of the orbits of comets has, in 
recent times (1819), in the most brilliant manner enriched our 
knowledge of" the solar system. Encke has discovered the ex- 
istence of a comet of so short a period of revolution that it re- 
mains entirely within the limits of our planetary system, at- 
taining its aphelion between the orbits of the smaller planets 
and that of Jupiter. Its eccentricity must be assumed at 0*845, 
that of Juno (which has the greatest eccentricity of any of the 
planets) being 0*255. Encke's comet has several times, al- 
though with difficulty, been observed by the naked eye, as in 
Europe in 1819, and, according to Riimker, in New Holland 
in 1822. Its period of revolution is about S^d years; but, 
from a careful comparison of the epochs of its return to its 
perihelion, the remarkable fact has been discovered that these 
periods have diminished in the most regular manner between 
the years 1786 and 1838, the diminution amounting, in the 
course of 52 years, to about lyVl^h. days. The attempt to 
brmg into unison the results of observation and calculation in 
the investigation of all the planetary disturbances, with the 
view of explaining this phenomenon, has led to the adoption 
of the very probable hypothesis that there exists dispersed in 
space a vaporous substance capable of acting as a resisting 
medium. This matter diminishes the tangential force, and 
with it the major axis of the comet's orbit. The value of the 
constant of the resistance appears to be somewhat different 
before and after the perihelion ; and this may, perhaps, be as- 

* Arago, in the Anniiaire, 1832, p. 217-220. Sir John Herschel, 
Asiron., § 488. 



COMElfc'. 107 

bribed to tlie altered form of the small nebulous star in the 
vi(dnity of the Sun, and to the action of the unequal density 
of the strata of cosmical ether. ^ These facts, and the inves- 
tigations to which they have led, belong to the most interest- 
ng results of modern astronomy. Encke's comet has been 
the means of leading astronomers to a more exact investiga- 
tion of Jupiter's mass (a most important point with reference 
\o the calculation of perturbations) ; and, more recently, the 
eourse of this comet has obtained for us the first determina- 
tion, although only an approximative one, of a smaller mass for 
Mercury. 

The discovery of Encke's comet, which had a period of only 
3id years, was speedily followed, in 1826, by that of another, 
Biela'a comet, whose period of revolution is 6|th years, and 
which is likewise planetary, having its aphelion beyond the 
orbit of Jupiter, but within that of Saturn. It has a fainter 
light than Encke's comet, and, like the latter, its motion is 
direct, while Halley's comet moves in a course opposite to that 
pursued by the planets. Biela's comet presents the first cer- 
tain example of the orbit of a comet intersecting that of the 
Earth. This position, with reference to our planet, may there- 
fore be productive of danger, if we can associate an idea of 
danger with so extraordinary a natural phenomenon, whose 
history presents no parallel, and the results of which we are 
consequently unable correctly to estimate. Small masses en- 
dowed with enormous velocity may certainly exercise a con- 
siderable power ; but Laplace has shovi^i that the mass of the 
comet of 1770 is probably not equal to jo'oo'tb of that of the 
Earth, estimating further with apparent correctness the incan 
mass of comets as much below yoo-Vo nth that of the Earth, 
or about yoVo^b that of the Moon.f We must not confound 
the passage of Biela's comet through the Earth's orbit with 
its proximity to, or collision with, our globe. When this pas- 
sage took place, on the 29th of October, 1832, it required a 
full month before the Earth would reach the point of inter- 
section of the two orbits. These two comets oi" short periods 
of revolution also intersect each other, and it has been justly 
observed,! that amid the many perturbations experienced by 

* Encke, in. the Astronomische Nachrichf en, 1843, No. 489, s. 130-132. 

■hLaplace, Expos, du S^/st. du Monde, p. 216, 237. 

X Littrow, Beschreibende Asiron,, 1835, s. 274. On the inner comet 
recently discovered by M. Faye, at the Observatory of Paris, and whose 
eccentricity is 0-551, its distance at its perihelion 1-690, and its distance 
at its aphelion 5-832, see Schumacher, Asiron. Nachr., 1844, No. 495. 
Regarding the supposed identity of the comet of 1766 with the third 



108 COSMOS. 

such small bodies from the larger planets, there is di. possibility 
— supposing" a meeting of these comets to occur in October — • 
that the inhabitants of the Earth may witness the extraordi- 
nary spectacle of an encounter between two cosmical bodies, 
and possibly of their reciprocal penetration and amalgamation, 
or of their destruction by means of exhausting emanations. 
Events of this nature, resulting either from deflection occa- 
sioned by disturbing masses or primevally intersecting orbits, 
must have been of frequent occurrence in the course of mill- 
ions of years in the immeasurable regions of ethereal space ; 
but they must be regarded as isolated occurrences, exercising 
no more general or alterative effects on cosmical relations than 
the breaking forth or extinction of a volcano within the limit- 
ed sphere of our Earth. 

A third interior comet, having likev/ise a short period of 
revolution, was discovered by Faye on the 22d of November, 
1843, at the Observatory at Paris. Its elliptic path, which 
approaches much more nearly to a circle than that of any 
other known comet, is included within the orbits of Mars and 
Saturn. This comet, therefore, which, according to Gold- 
schmidt, passes beyond the orbit of Jupiter, is one of the few 
whose perihelia are beyond Mars. Its period of revolution is 
7y-/o years, and it is not improbable that the form of its pres- 
ent orbit may be owing to its great approximation to Jupiter 
at the close of the year 1839. 

If we consider the comets in their inclosed elliptic orbits as 
members of our solar system, and with respect to the length 
of their major axes, the amount of their eccentricity, and their 
periods of revolution, we shall probably find that the three 
planetary comets of Encke, Biela, and Faye are most nearly 
approached in these respects, first, by the comet discovered in 
1766 by Messier, and which is regarded by Clausen as iden- 
tical with the third comet of 1819; and, next, by the fourth 
comet of the last-mentioned year, discovered by Blaupain, but 
considered by Clausen as identical with that of the year 1743, 
and whose orbit appears, like that of Lexell's comet, to have 
suffered great variations from the proximity and attraction of 
Jupiter. The two last-named comets would likewise seem to 
have a period of revolution not exceeding five or six years, and 
their aphelia are in the vicinity of Jupiter's orbit. Among 
the comets that have a period of revolution of from seventy to 

comet of 1819, see Astr. Nachr., 1833, No. 239 ; and on the identity of 
the comet of 1743 and the fourth comet of 1819, see No. 237 of the last 
mentioned work. 



COMETS. 109 

seventy-six years, the first in point of importance with respect 
to theoretical and physical astronomy is Halley's comet, whose 
last appearance, in 1835, was much less brilliant than was to 
be expected from preceding ones ; next we would notice Ol- 
bers's comet, discovered on the 6th of March, 1815 ; and, 
lastly, the comet discovered by Pons in the year 1812, and 
whose elliptic orbit has been determined by Encke. The two 
latter comets were invisible to the naked eye. We now know 
with certainty of nine returns of Halley's large comet, it hav- 
ing recently been proved by Laugier's calculations,* that in 
the Chinese table of comets, first made known to us by Ed- 
ward Biot, the comet of 1378 is identical with Halley's ; its 
periods of revolution have varied in the interval between 1378 
and 1835 from 74-91 to 77-58 years, the mean being 76-1. 

A host of other comets may be contrasted with the cosmical 
bodies of which we have spoken, requiring several thousand 
years to perform their orbits, which it is difficult to determine 
with any degree of certainty. The beautiful comet of 1811 
requires, according to Argelander, a period of 3065 years for 
its revolution, and the colossal one of 1680 as much as 8800 
years, according to Encke's calculation. These bodies respect- 
ively recede, therefore, 21 and 44 times further than Uranus 
from the Sun, that is to say, 33,600 and 70,400 millions of 
miles. At this enormous distance the attractive force of the 
Sun is still manifested ; but while the velocity of the comet 
of 1680 at its perihelion is 212 miles in a second, that is, 
thirteen times greater than that of the Earth, it scarcely 
moves ten feet in the second when at its aphelion. This ve- 
locity is only three times greater than that of water in our 
most sluggish European rivers, and equal only to half that 
which I have observed in the Cassiquiare, a branch of the 
Orinoco. It is highly probable that, among the innumerable 
host of uncalculated or undiscovered comets, there are many 
whose major axes greatly exceed that of the comet of 1680. 
In order to form some idea by numbers, I do not say of the 
sphere of attraction, but of the distance in space of a fixed star 
or other sun, from the aphelion of the comet of 1680 (the fur- 
thest receding cosmical body with which we are acquainted 
in our solar system), it must be remembered that, according 
to the most recent determinations of parallaxes, the nearest 
fixed star is full 250 times further removed from our sun than 
the comet in its aphelion. The comet's distance is only 44 

* Laugier, in the Comptes Rendus des Stances de f Academie, 18431 
t xvi., p. 1006. 



110 COSMOS. 

times that of Uranus, while a Centaiiri is 11,000, and 61 
Cygni 31,000 times that of Uranus, according to Bessel's de- 
terminations. 

Having considered the greatest distances of comets from 
the central body, it now remains for us to notice instances of 
the greatest proximity hitherto measured. Lexell and Burck- 
hardt's comet of 1770, so celebrated on account of the disturb- 
ances it experienced from Jupiter, has approached the Earth 
within a smaller distance than any other comet. On the 28th 
of June, 1770, its distance from the Earth was only six times 
that of the Moon. The same comet passed twice, viz., in 
]769 and 1779, through the sj^stem of Jupiter's four satellites 
without producing the slightest notable change in the well- 
known orbits of these bodies. The great comet of 1680 ap- 
proached at its perihelion eight or nine times nearer to the 
surface of the Sun than Lexell's comet did to that of our 
Earth, being on the 17th of December a sixth part of the 
Sun's diameter, or seven tenths of the distance of the Moon 
from that luminary. Perihelia occurring beyond the orbit of 
Mars can seldom be observed by the inhabitants of the Earth, 
owing to the faintness of the light of distant comets ; and 
among those already calculated, the comet of 1729 is the only 
one which has its perihelion between the orbits of Pallas and 
Jupiter ; it was even observed beyond the latter. 

Since scientific knowledge, although frequently blended with 
vague and superficial views, has been more extensively diffused 
through wider circles of social life, apprehensions of the possi- 
ble evils threatened by comets have acquired more weight as 
their direction has become more defuiite. The certainty that 
there are within the known planetary orbits comets which re- 
visit our regions of space at short intervals — that great dis- 
turbances have been produced by Jupiter and Saturn in their 
orbits, by which such as were apparently harmless have been 
converted into dangerous bodies — the intersection of the Earth's 
orbit by Biela's comet — the cosmical vapor, which, acting as 
a resisting and impeding medium, tends to contract all orbits 
— the individual difference of comets, which would seem to 
indicate considerable decreasing gradations in the quantity of 
the mass of the nucleus, are all considerations more than equiv- 
alent, both as to number and variety, to the vague fears en- 
tertained in early ages of the general conflagration of the world 
hy Jiammg stvords, and stars with fieri/ streaming hair. As 
the cons'Dlatory considerations which may be derived from the 
calculus of probabilities address themselves to reason and to 



AEROLITES. Ill 

meditative understanding only, and not to the imagination or 
to a desponding condition of mind, modern science has been 
accused, and not entirely without reason, of not attempting to 
allay apprehensions which it has been the very means of ex- 
citino-. It is an inherent attribute of the human mind to ex- 
perience fear, and not hope or joy, at the aspect of that which 
is unexpected and extraordinary.* The strange form of a large 
comet, its faint nebulous light, and its sudden appearance in 
the vault of heaven, have in all regions been almost invariably 
regarded by the people at large as some new and formidable 
agent inimical to the existing state of things. The sudden 
occurrence and short duration of the phenomenon lead to the 
belief of some equally rapid reflection of its agency in terres- 
trial matters, whose varied nature renders it easy to find events 
that may be regarded as the fulfillment of the evil foretold by 
the appearance of these mysterious cosmical bodies. In our 
own day, however, the public mind has taken another and 
more cheerful, although singular, turn with regard to comets ; 
and in the German vineyards in the beautiful valleys of the 
Rhine and Moselle, a belief has arisen, ascribing to these once 
ill-omened bodies a beneficial influence on the ripening of the 
vine. The evidence yielded by experience, of which there is 
no lack in these days, when comets may so frequently be ob- 
served, has not been able to shake the common belief in the 
meteorological myth of the existence of wandering stars capa- 
ble of radiating heat. 

From comets I would pass to the consideration of a far more 
enigmatical class of agglomerated matter — the smallest of all 
asteroids, to which we apply the name aeTolites, or meteoric 
stones,^ when they reach our atmosphere in a fragmentary 
condition. If I should seem to dwell on the specific enumer- 
ation of these bodies, and of comets, longer than the general 
nature of this work might w^arrant, I have not done so unde- 
signedly. The diversity existing in the individual character- 
istics of comets has already been noticed. The imperfect 
knowledge we possess of their physical character renders it 

* Fries, Vorlesungen uber die SternJcunde, 1833, s. 262-267 (Lectures 
on the Science of Astronomy). An infeUcitously chosen instance of the 
good omen of a comet may be found in Seneca, Nat. Qucest., vii., 17 and 
21. The philosopher thus writes of the comet: " Quern 7ios Neronis 
principatu Icetissimo vidimus et qui cometis detraxit infamiam.^' 

t [Much valuable information may be obtained regarding the origin 
and composition of aerolites or meteoric stones in Memoirs on the sub- 
ject, by Baumbeer and other writers, in the numbers of Poggendorf's 
Annalen, from 1845 to the present time.] — Tr. 



1 12 COSMOS. 

difficult; in a work like the present, to give the proper def^ree 
of circumstantiality to the phenomena, which, althougL of 
frequent recurrence, have been observed with such various de- 
grees of accuracy, or to separate the necessary from the acci- 
dental. It is only with respect to measurements and compu- 
tations that the astronomy of comets has made any marked 
advancement, and, consequently, a scientific consideration of 
these bodies must be limited to a specification of the differencef 
of physiognomy and conformation in the nucleus and tail, the 
instances of great approximation to other cosmical bodies, and 
of the extremes in the length of their orbits and in their periods 
of revolution. A faithful delineation of these phenomena, as 
well as of those which we proceed to consider, can only be 
given by sketching individual features with the animated cir- 
cumstantiality of reality. 

Shooting stars, fire-balls, and meteoric stones are, with great 
probability, regarded as small bodies moving with planetary 
velocity, and revolving in obedience to the laws of general 
gravity in conic sections round the Sun. When these masses 
meet the Earth in their course, and are attracted by it, they 
enter within the limits of our atmosphere in a luminous con- 
dition, and frequently let fall more or less strongly heated stony 
fragments, covered with a shining black crust. When we 
enter mto a careful investigation of the facts observed at those 
epochs when showers of shooting stars fell periodically in Cu- 
mana in 1799, and in North America during the years 1833 
and 1834, we shall find XhdX fire-balls can not be considered 
separately from shooting stars. Both these phenomena are 
frequently not only simultaneous and blended together, but 
they likewise are often found to merge into one another, the 
one phenomenon gradually assuming the character of the other 
alike with respect to the size of their disks, the emanation of 
sparks, and the velocities of their motion. Although explod- 
ing smoking luminous fire-balls are sometimes seen, even in 
the brightness of tropical daylight,* equaling in size the ap- 

* A friend of mine, much accustomed to exact trigonometrical meas- 
urements, was in the year 1788 at Popayan, a city which is 2^ 26' 
north latitude, lying at an elevation of 5583 feet above the level of the 
sea, and at noon, when the sun was shining brightly in a cloudless sky, 
saw his room lighted up by a fire-ball. He had his back to tlie window 
at the time, and on turning round, perceived that great part of the path 
traversed by the fire-ball was still illuminated by the brightest radiance 
Different nations have had the most various terms to exjiress the^e i>iie- 
uomena : the Germans use the w^ord Sternschnnppe, literally star savff 
—an expression well suited to the physical views of the vulgar in former 



AEROLITES. 1]3 

parent diameter of the Moon, innumerable quantities of shoot- 
ing stars have, on the other hand, been observed to fall in 
forms of such extremely small dimensions that they appear 
only as moving points or pliosiohorescent lines.^ 

It still remains undetermined whether the many luminous 
bodies that shoot across the sky may not vary in their nature. 
On my return from the equinoctial zones, I was impressed 
with an idea that in the torrid regions of the tropics I had 
more frequently than in our colder latitudes seen shooting 
stars fall as if from a height of twelve or fifteen thousand feet ; 
that they were of brighter colors, and left a more brilliant line 
of light in their track ; but this impression was no doubt owing 
to the greater transparency of the tropical atmosphere,! which 

times, according to which, the lights in the finnament were said to under 
go a process of snuffing or cleaning ; and other nations generally adopt a 
term expressive of a shot ov fall of stars, as the Swedish stjernjfall, the 
Italian stella cadente, and the English star shoot. In the woody district 
of the Orinoco, on tlie dreary banks of the Cassiquiare, I heard the na- 
tives in the Mission of Vasiva use terms still more inelegant than the 
German star snnff. {Relation Historique du Voy. aux Rigions Equhwx., 
t. ii., p. 513.) These same tribes term the pearly drops of dew which 
cover the beautiful leaves of the heliconia star spit. In the Lithuanian 
mythology, the imagination of the people has embodied its ideas of the 
nature and signification of falling stars under nobler and more graceful 
symbols. The Parcse, Werpeja, weave in heaven for the new-born 
child its thread of fate, attaching each separate thread to a star. When 
death approaches the person, the thread is rent, and the star wanes and 
sinks to the earth. Jacob Grimm, Deutsche Mytlwlogie, 1843, s. 685. 

* According to the testimony of Professor Denison Olmsted, of Yale 
College, New Haven, Connecticut. (See Poggend., Annalen der Physik, 
bd. XXX., s. 194.) Kepler, who excluded tire-balls and shooting stars 
from the domain of astronomy, because they were, according to his 
views, -'meteors arising from the exhalations of the earth, and blend- 
ing with the higher ether," expresses himself, however, generally with 
much caution. He says: " Stellce cadentes sunt materia viscida inflam- 
mata. Eai"nm aliqufs inter cadendum absumuntur, aliquce vere in terram 
cadunt. pondere sua tractce. Nee est dissimile vero, quasdam conglohataa 
esse ex materia fcecidentd, in ipsam auram atheream immixta : exque 
aetheris regione, tractu rectilineo, per aerem trajicerc, ceu minutos com- 
etas, occulta causa motus utrorumque.^^ — Kepler, Epit. Astron. Coper- 
nicance, t. i., p. 80. 

t Relation Historique, t. i., p. 80, 213, 527. If in falling stars, as in 
comets, we distinguish between the head or nucleus and the tail, we 
shall find that the gi-eater transparency of the atmosphere in tropical 
climates is evinced in the greater length and brilliancy of the tail which 
may be observed in those latitudes. The phenomenon is therefore not 
necessarily more frequent there, because it is oftener seen and contin- 
ues longer visible. The influence exercised on shooting stars by the 
character of the atmosphere is shown occasionally even in our temper- 
ate zone, and at veiy small distances apart. Wartmann relates that on 
the occasion of a November phenomenon at two places lying very near 



114 COSMOS. 

enables the eye to penetrate furtlier into distance. Sir Alex- 
ander Burnes likewise extols as a consequence of the purity of 
the atmosphere in Bokhara the enchanting and constantly-re- 
curring spectacle of variously-colored shooting stars. 

The connection of meteoric stones with the grander phe- 
nomenon of fire-halls — the former being known to be project- 
ed from the latter with such force as to penetrate from ten 
to fifteen feet into the earth — has been proved, among many 
other instances, in the falls of aerolites at Barbotan, in the 
Department des Landes (24th July, 1790), at Siena (16th 
June, 1794), at Weston, in Connecticut, U. S. (14th Decem- 
ber, 1807), and at Jnvenas, in the Department of Ardeche 
(15th June, 1821). Meteoric stones are in some instances 
thrown from dark clouds suddenly formed in a clear sky, and 
fall with a noise resembling thunder. Whole districts have 
thus occasionally been covered with thousands of fragmentary 
masses, of uniform character but unequal magnitudes, that 

each other, Geneva and Aux Plancliettes, the number of the meteors 
counted wei'e as 1 to 7. (Wartmann, Mem. sur les Eloiles Jilanies, p. 
17.) The tail of a shooting star (or its train), on the subject of which 
Brandes has made so many exact and delicate observations, is in no 
way to be ascribed to the continuance of the impression produced by 
light on the retina. It sometimes continues visible a w^hole minute, 
and in some rare instances longer than the light of the nucleus of the 
shooting star; in which case the luminous track remains motionless. 
(Gilb., Ann., bd. xiv., s. 251.) This circumstance further indicates the 
analogy between large shooting stars and fire-balls. Admiral Krusen- 
stern saw, in his voyage round the world, the train of a fire-ball shine 
for an hour after the luminous body itself had disappeared, and scarce- 
ly move throughout the whole time. {Reise, th. i., s. 58.) Sir Alex- 
ander Bumes gives a charming description of the transparency of the 
clear atmosphere of Bokhara, which was once so favorable to the pur- 
suit of astronomical observations. Bokhara is situated in 39° 43' north 
latitude, and at an elevation of 1280 feet above the level of the sea. 
" There is a constant serenity in its atmosphere, and an admirable clear- 
ness in the sky. At night, the stars have uncommon luster, and the 
Milky Way shines gloriously in the firmament. There is also a never- 
ceasing display of the most brilliant meteors, which dart like rockets 
in the sky ; ten or twelve of them are sometimes seen in an hour, as- 
suming every color — fiery red, blue, pale, and faint. It is a noble 
country for astronomical science, and great must have been the ad- 
vantage enjoyed by the famed observatory of Samarkand." (Burnes, 
Travels into Bokhara, vol. ii. (1834), p. 158.) A mere traveler must 
not be reproached for calling ten or twelve shooting stars in an hour 
*' many," since it is only recently that we have learned, from careful 
observations on this subject in Europe, that eight is the mean number 
which may be seen in an hour in the field of vision of one individual 
(Quetelet, Corresp. Mathim., Novem., 1837, p. 447); this number is, 
however, limited to five or six by that diligent observer, Olbers. 
(Schum., Jahrh., 1838, s. 325.) 



AEROLITES. 115 

nave been liiirled from one of these moving clouds. In less 
frequent cases, as in that which occurred on the 16th of Sep- 
tember, 1843, at Kleinwenden, near Miililhausen, a large 
aerolite fell with a thundering crash while the sky was clear 
and cloudless. The intimate affinity between fire-balls and 
shooting stars is further proved by the fact that fire-balls, from 
which meteoric stones have been thrown, have occasionally 
been found, as at Angers, on the 9th of June, 1822, having a 
iiameter scarcely equal to that of the small fire-works called 
Eloraan candles. 

The formative power, and the nature of the physical and 
chemical processes involved in these phenomena, are questions 
ill equally shrouded in mystery, and we are as yet ignorant 
tvdiether the particles composing the dense mass of meteoric 
itones are originally, as in comets, separated from one another 
\n the form of vapor, and only condensed v/ithin the fiery ball 
when they become luminous to our sight, or whether, in the 
ease of smaller shooting stars, any compact substance actually 
Tails, or, finally, whether a meteor is composed only of a smoke- 
like dust, "containing iron and nickel ; while w^e are wholly 
ignorant of what takes place within the dark cloud from which 
a noise like thunder is often heard for many minutes before 
the stones fall.* 

* Oil meteoric dust, see Arago, in the Annuaire for 1832, p. 254. 1 
have very recently endeavored to show, in another work {Asie Centrale, 
t. i., p. 408), how the Scythian saga of the sacred gold, which fell burn- 
ing from heaven, and remained in'the possession of the Golden Horde 
of the ParalattB (Herod., iv., 5-7), probably originated in the vague rec- 
ollection of the fall of an aSrolite. The ancients had also some strange 
fictions (Dio Cassius, Ixxv., 1259) of silver which had fallen from heav- 
en, and with which it had been attempted, under the Emperor Seve- 
rus, to cover bronze coins ; metallic iron was, however, known to exist 
hi meteoric stones. (Plin., ii., 56.) The frequently-recui'ring expres- 
sion lapidibus phiit must not always be understood to refer to falls of 
aSrolites. In Liv., xxv., 7, it probably refers to pumice (rapil/i) eject- 
ed from the volcano, Mount Albanus (Monte Cavo), which vC-as not 
wholly extinguished at the time. (See Heyne, Opuscula Acad., t. iii., 
p. 261 ; and my Relation Hist., t. i., p. 394.) The contest of Hercules 
with the Ligyans, on the road from the Caucasus to the Hesperides, 
belongs to a different sphere of ideas, being an attempt to explain myth- 
ically the origin of the round quartz blocks in the Ligyan field of stones 
at the mouth of the Rhone, which Aristotle supposes to have been eject- 
ed from a fissure during an earthquake, and Posidonius to have been 
caused by the force of the waves of an inland piece of water. In the 
fragments that we still possess of the play of ^Eschylus, the Promeihetis 
Delivered, every thing proceeds, however, in part of the narration, as 
in a fall of aerolites, for Jupiter draws together a cloud, and causes the 
"district around to be covered by a shower of round stones " Posido- 



116 COSMOS. 

We can ascertain by measurement the enormous, wonder, 
ful, and wholly planetary velocity of shooting stars, fire-balls, 
and meteoric stones, and we can gain a knowledge of what is 
the general and uniform character of the phenomenon, but 
not of the genetically cosmical process and the results of the 
metamorphoses. If meteoric stones while revolving in space 
are already consolidated into dense masses,* less dense, how- 

uius even ventured to deride the geognostic myth of the blocks and 
stones. The Lygian field of stones was, however, very naturally and 
well described iSy the ancients. The district is now known as La Crau. 
(See Guerin, Mesures Baromitriques dans les Alpes, et Metiorologie 
d^ Avignon, 1829, chap, xii., p. 115.) 

* The specific weight of aerolites varies from 1-9 (Alais) to 4-3 
(Tabor). Their general density maybe set down as 3, water being 1. 
As to wliat has been said in the text of the actual diameters of fire-balls, 
we must remark, that the numbers have been taken froin the few 
measurl&ments that can be relied upon as correct. These give for the 
fire-ball of Weston, Connecticut (14th December, 1807), only 500; for 
that observed by Le Roi (10th July, 1771) about 1000, and for that 
estimated by Sir Charles Blagden (18th January, 1783) 2600 feet iu 
diameter. Brandes {UnterhaltHugen, bd. i., s. 42) ascribes a diameter 
varying from 80 to 120 feet to shooting stars, and a luminous train ex- 
tending from 12 to 16 miles. There are, however, ample optical caus- 
es for supposing that the appai'ent diameter of fire-balls and shooting 
stars has been very much overrated. The volume of the largest fiie- 
ball yet observed can not be compared with that rf Ceres, estimating 
this planet to have a diameter of only 7J English miles. (See the 
generally so exact and admirable treatise, i )n the Connection of the 
Physical Sciences, 1835, p. 411.) With the view of elucidating what 
has been stated in the text regarding the large aerolite that fell into 
the bed of the River Narni, but has not again been found, I will give 
the passage made known by Pertz, trom the Chronicon Benedicti, Man- 
achi Sancti Andrece in Monte Soracte, a MS. belonging to the tenth 
century, and preserved in the Chigi Library at Rome. The barbaious 
Latiji of that age has been left unchanged. '^^ Anno 921, temporihns 
domini Johannis Decimi pape, in anno pontificatus illius 7 visa sunt sig- 
na. Nam juxta urbem Romani lapides plurimi de cailo cadere visi sunt. 
In civitate qua; vocatur Narnia tarn diri ac tetri, ut 7iihil aliitd credatur, 
quarn de infernalibiis locis dedncti essent. Nam ila ex illis lapidibus 
umis omnium maximns est, ut d-]cidens in fluuien Narnvs, ad mensuram 
unius c'uhiti super aquas fiumim ', usque hodie videretur. Nam et ignitiB 
faculce de coslo plurimoe omnibus in hac civitate Romani popuH vis<e S7int, 
ita ut pene terra contingeret. Alice cadentes,^'' &c. (Pertz, Mmivm. 
Germ. Hist. Scriptores, t. iii., p. 715.) On the aerolites of ^gos. I'ota- 
mos, which fell, according to the Parian Chronicle, in the 78 1 Olym- 
piad, see Bockh, Corp. Jnscr. Graec, t. ii., p. 302, 320, 340; also Aris- 
tot., Meteor., i., 7 (Ideler's Comm., t. i., p. 404-407) ; Stob., Eel. Phys., 
I., 25, p. 508 (Heeren); Pint., Lys., c. 12; Diog. Laert., ii., 10; and 
see, also, subsequent notes in this work. According to a Moui^oliun 
tradition, a black fragment of a rock, forty feet in height, fell iVoni 
heaven on a plain near the source of the Great Yellow River in West- 
ern China. (Abel Remusat, in Lametherie, Jour, de Phys., 1819, Mai 
p. 264.) 



AEROLITES. 117 

ever, than the mean density of the earth, they must be very 
small nuclei, which, surrounded by inflammable vapor or gas, 
form the innermost part of fire-balls, from the height and ap- 
parent diameter of which we may, in the case of the largest, 
estimate that the actual diameter varies from 500 to about 
2800 feet. The largest meteoric masses as yet known are 
those of Otumpa, in Chaco, and of Bahia, in Brazil, described 
by Rubi de Celis as being from 7 to 7|- feet in length. The 
meteoric stone of ^gos Potamos, celebrated in antiquity, and 
even mentioned in the Chronicle of the Parian Marbles, which 
fell about the year m which Socrates was born, has been de- 
scribed as of the size of two mill-stones, and equal in weight 
to a full wagon load. Notwithstanding the failure that has 
attended the efforts of the African traveler. Brown, I do not 
wholly relinquish the hope that, even after the lapse of 2312 
years, this Thracian meteoric mass, which it would be so dif- 
ficult to destroy, may be found, since the region in which it 
fell is now become so easy of access to European travelers. 
The huge aerolite which in the beginning of the tenth centu- 
ry fell into the river at Narni, projected between three and 
four feet above the surface of the water, as we learn from a 
document lately discovered by Pertz. It must be remarked 
that these meteoric bodies, whether in ancient or modern times, 
can only be regarded as the principal fragments of masses that 
have been broken up by the explosion either of a fire-ball or 
a dark cloud. 

On considering the enormous velocity with \Vhich, as has 
been mathematically proved, meteoric stones reach the earth 
from the extremest confines of the atmosphere, and the length- 
ened course traversed by fire-balls through the denser strata 
of the air, it seems more than improbable that these metallif- 
erous stony masses, containing perfectly-formed crystals of oli- 
vine, labradorite, and pyroxene, should in so short a period of 
time have been converted from a vaporous condition to a solid 
nucleus. Moreover, that which falls from meteoric masses, 
even where the internal composition is chemically difierent, 
exhibits almost always the peculiar character of a fragment, 
being of a prismatic or truncated pyramidal form, with broad, 
somewhat curved faces, and rounded angles. But whence 
comes this form, which was first recognized by Schreiber as 
characteristic of the severed part of a rotating planetary body 1 
Here, as in the sphere of organic life, all that appertains to 
the history of development remains hidden in obscurity. Me- 
teoric masses become luminous and kindle at heights which 



118 COSMOS. 

must be regarded as almost devoid of air, or occupied by an 
atmosphere that does not even contain To"oVoo*h part of oxy 
gen. The recent investigations of Biot on the important phe 
nomenon of twihght=^ have considerably lowered the lines 
which had, perhaps with some degree of temerity, been usual 
ly termed the boundaries of the atmosphere ; but processes of 
hght may be evolved independently of the presence of oxygen, 
and Poisson conjectured that aerolites were ignited far beyond 
the range of our atmosphere. Numerical calculation and geo- 
metrical measurement are the only means by which, as in the 
case of the larger bodies of our solar system, we are enabled to 
impart a firm and safe basis to our investigations of meteoric 
stones. Although Halley pronounced the great fire-ball of 1686, 
whose motion was opposite to that of the earth in its orbit, f to 
be a cosmical body, Chladni, in 1794, first recognized, with 
ready acuteness of mind, the connection between fire-balls and 
the stones projected from the atmosphere, and the motions of the 
former bodies in space. J A brilliant confirmation of the cos- 
mical origin of these phenomena has been afforded by Denison 
Olmsted, at New Haven, Connecticut, who has shown, on the 
concurrent authority of all eye-witnesses, that during the cele- 
brated fall of shooting stars on the night between the 12th 

* Biot, TraiU d' Astro7iomie Physique (3eme 6d.), 1841, t. i., p. 149, 
177, 238, 312. My lamented frieud Poisson endeavored, in a singular 
manner, to solve the difficulty attending an assumption of the sponta- 
neous ignition of meteoric stones at an elevation where the density of 
the atmosphere is almost null. These are his words : '' It is difficult to 
attribute, as is usually done, the incandescence of aerolites to friction 
against the molecules of the atmosphere at an elevation above the earth 
where the density of the air is almost null. May we not suppose that 
the electric fluid, in a neutral condition, forms a kind of atmosphere, ex- 
tending far beyond the mass of our atmosphere, yet subject to terres- 
trial attraction, although physically imponderable, and consequently 
following our globe in its motion ? According to this hypothesis, the 
bodies of which we have been speaking would, on entering this im- 
ponderable atmosphere, decompose the neutral fluid by their unequal 
action on the two electricities, and they would thus be heated, and in 
a state of incandescence, by becoming electrified." (Poisson, Rech. sur 
la Probability des Jugements, 1837, p. 6.) 

t Philos. Transact., vol. xxix., p. lGl-163. 

X The first edition of Chladni's important treatise, Ueber den Ur- 
sprung der von Pallas gefundenen nnd anderen Eisenmassen (On the 
Origin of the masses of Iron found by Pallas, and other similar masses), 
appeared two months prior to the shower of stones at Siena, and two 
years before Lichtenberg stated, in the Gottingen Taschenbnch, tha 
" stones reach our atmosphere from the remoter regions of space.' 
Comp., also, Olbers's letter to Benzenberg, 18th Nov., 1837, in Ben 
zenberg's Treatise on Shooting Stars, p. 186. 



AEROLITES. 119 

and 13th of November, 1833, the fire-balls and shooting stars 
all emerged from one and the same quarter of the heavens, 
namely, in the vicinity of the star y in the constellation Leo, 
and did not deviate from this point, although the star changed 
its apparent height and azimuth during the time of the observ- 
ation. Such an independence of the, Earth's rotation shows 
that the luminous body must have reached our atmosphere from 
witlwut. According to Encke's computation* of the whole 

* Eucke, \i\Vo^§,end., Annalen, bd. xxxiii. (1834), s. 213. Arago, 
in the Annuaire. for 1836, p. 291. Two letters which I wrote to Ben- 
zenberg, May 19 and October 22, 1837, on the conjectural precession 
of the nodes in the orbit of periodical falls of shooting stai's. (Benzen- 
berg's Sternsch., s. 207 and 209.) Olbers subsequently adopted this 
opinion of the gradual retardation of the November phenomenon. 
{Astron. Nachr., 1838, No. 372, s. 180.) If I may venture to combine 
two of the falls of shooting stars mentioned by the Arabian writers 
with the epochs found by Boguslawski for the fourteenth century, I 
obtain the following more or less accordant elements of the movements 
of the nodes : 

In Oct., 902, on the night in which King Ibrahim ben Ahmed died, 
there fell a heavy shower of shooting stars, ** like a fiery rain ;" and 
this year was, therefore, called the year of stars. (Conde, Hist, de la 
Domin. de los Arabes, p. 346.) 

On the 19th of Oct., 1202, the stars were in motion all night. " They 
fell like locusts." {Comptes Rendus, 1837, t. i., p. 294 ; and Fryehn, in 
the Bull, de V Academie de St. PHershourg, t. iii., p. 308.') 

On the 21st Oct., O.S., 1366, " die sequente post festum XL ynillia Vir- 
ginum ab hora matutiyia usque ad Tioram primam visce sunt quasi stellce 
de coilo cadere contiinio, et in tanta multitudine, quod nemo narrare suf 
jicit.'''' This remarkable notice, of which we shall speak more fully in 
the subsequent part of this w^ork, was found by the younger Von Bo- 
guslawski, in Benesse (de Horowic) de Weitmil or Weithmiil, Chron- 
icon Ecclesice Pragensis, p. 389. This chronicle may also be found in 
the second part of ScHptores rerum Bghemicarum, by Pelzel and Do- 
browsky, 1784. (Schum., Astr. Nachr., Dec, 1839.) 

On the night between the 9th and 10th of November, 1787, many fall- 
ing stars were observed at Manheira, Southern Germany, by Hemmer. 
(Kamtz, Meteor., th. iii., s. 237.) 

After midnight, on the 12th of November, 1799, occurred the extra- 
ordinary fall of stars at Cumana, which Bonpland and myself have de 
scribed, and which was observed over a great part of the earth. (Relat. 
Hist., t. i., p. 519-527.) 

Between the 12th and 13th of November, 1822, shooting stars, inter- 
mingled with fire-balls, were seen in large numbers by Kloden, at 
Potsdam. (Gilbei-t's Ann., bd. Ixxii., s. 291.) 

On the I3th of November, 1831, at 4 o'clock in the morning, a great 
shower of falling stars was seen by Captain Berard, on the Spanish 
coast, near Carthagena del Levante. {Annuaire, 1836, p. 297.) 

In the night between the 12th and 13tli of November, 1833, occurred 
the phenomenon so admirably described by Professor Olmsted, iu 
North America. 

In the night of the 13-14th of November, 1834, a similar fall of shoot- 



120 COSMOS. 

Qumber of observations made in the United States of North 
America, between the thirty-fifth and the forty-second degrees 
of latitude, it would appear that all these meteors came from 
the same point of space in the direction in which the Earth 
was moving at the time. On the recurrence of falls of shoot- 
ing stars in North America, in the month of November of the 
years 1834 and 1837, and in the analogous falls observed at 
Bremen in 1838, a like general parallelism of the orbits, and 
the same direction of the meteors from the constellation Leo, 
were again noticed. It has been supposed that a greater 
parallelism was observable in the direction of periodic falls of 
shooting stars than in those of sporadic occurrence ; and it has 
further been remarked, that in the periodically-recurring falls 
in the month of August, as, for instance, in the year 1839, the 
meteors came principally from one point between Perseus and 
Taurus, toward the latter of which constellations the Earth 
was then moving. This peculiarity of the phenomenon, mani- 
fested in the retrograde direction of the orbits in November 
and August, should be thoroughly investigated by accurate 
observations, in order that it may either be fully confirmed or 
refuted. 

The heights of shooting stars, that is to say, the heights of 
the points at which they begin and cease to be visible, vary 
exceedingly, fluctuating between 16 and 140 miles. This 
important result, and the enormous velocity of these problem- 
atical asteroids, were first ascertained by Benzenberg and 
Brandes, by simultaneous observations and determinations of 
parallax at the extremities of a base line of 49,020 feet in 
length. =^ The relative velocity of motion is from 18 to 36 
miles in a second, and consequently equal to planetary velocity. 
This planetary velocity,! as well as the direction of the orbits 

jng stars was seen in North America, although the numbers were not 
quite so considerable. (Poggend., Annalen, bd. xxxiv., s. 129.) 

On the 13th of November, 1835, a barn was set on fire by the fall of 
a sporadic fire-ball, at Belley, in the Department de I'Ain. {Annuaire, 
1836, p. 296.) 

In the year 1838, the stream showed itself most decidedly on the 
night of the 13-14th of November. {Astron. Nachr., 1838, No. 372.) 

* I am well aware tliat, amoug the 62 shooting stars simultaneously 
observed in Silesia, in 1823, at the suggestion of Professor Brandes 
some appeared to have an elevation of 183 to 240, or even 400 miles. 
(Bi'andes, Unterhaltungen fur Frennde der Astronomic mid Physik, heft 
i., s. 48. Instructive Nairatives for the Lovers of Astronomy and Phys- 
ics.) But Olbers considered that all determinations for elevations be- 
yond 120 miles must be doubtfid, owing to the smallness of the parallax. 

t The planetary velocity of translation, the movement in the orbit, is 
in Mercury 26-4, in Venus 19-2, and in the Earth 16-4 miles in a second 



AEROLITES. 121 

of fire-balls and shooting stars, wliicli has frequently been ob- 
served to be opposite to that of" the Earth, ma}^ be considered 
as conclusive arguments against the hypothesis that aerolites 
derive their origin from the so-called active lunar volcanoes. 
Numerical views regarding a greater or lesser volcanic force 
on a small cosmical body, not surrounded by any atmosphere, 
must, from their nature, be wholly arbitrary. We may imag- 
ine the reaction of the interior of a planet on its crust ten or 
even a hundred times greater than that of our present terres- 
• trial volcanoes ; the direction of masses projected from a satel- 
lite revolving from west to east might appear retrogressive, 
owing to the Earth in its orbit subsequently reaching that 
point of space at which these bodies fall. If we examine the 
whole sphere of relations which I have touched upon in this 
work, in order to escape the charge of having made unproved 
assertions, we shall find that the hypothesis of the selenic ori- 
gin of meteoric stones* depends upon a number of conditions 

* Chladui states that an Italian physicist, Paolo Maria Terzago, on 
the occasion of the fall of an aerolite at Milan in 1660, by which a Fran- 
ciscan monk was killed, was the first who surmised that aerolites were 
of selenic origin. He says, in a memoir entitled Musceuvi Septalianum, 
Manfredi Septalcs, Patricii Mediolanensis, indjistrioso labore conslruciurn 
(Tortona, 1664, p. 44), '^Labant philosophorum meutes sub horum lapidum 
ponderibus ; ni dicire velimus, lunam terram alteram, sine mundum esse, 
ex cujus montibus dwisa frustra in inferior em nostrum hunc orbe^n dela 
bantury Without any previous knowledge of this conjecture, Olbers 
was led, in the year 1795 (after the celebrated fall at Siena on the 16th 
of June, 1794), into an investigation of the amount of the initial tangen- 
tial force that would be requisite to bring to the Earth masses project- 
ed from the Moon. This ballistic problem occupied, during ten or 
twelve years, the attention of the geometricians Laplace, Biot, Brandes, 
and Poisson. The opinion which w^as then so prevalent, but which has 
since been abandoned, of the existence of active volcanoes in the Moon, 
where air and water are absent, led to a confusion in the minds of the 
generality of persons between mathematical possibilities and physical 
probabilities. Olbers, Brandes, and Chladni thought *' that the velocity 
of 16 to 32 miles, with which fire-balls and shooting stars entered our 
atmosphere," furnished a refutation to the view of their selenic origin. 
According to Olbers, it would require to reach the Earth, setting aside 
the resistance of the air, an initial velocity of 8292 feet in the second ; 
according to Laplace, 7862 ; to Biot, 8282 ; and to Poisson, 7595. La- 
place states that this velocity is only five or six times as great as that of 
a cannon ball; but Olbers has sliown "that, with such an initial veloc- 
ity as 7500 or 8000 feet in a second, meteoric stones would arrive at the 
surface of our earth with a velocity of only 35.000 feet (or 1-53 German 
geogi'aphical mile). But the measured velocity of meteoric stones av- 
erages five such miles, or upward of 114,000 feet to a second ; and, 
consequently, the original velocity of projection from the Moon must 
be almost 110,000 feet, and therefore fourteen times greater than La- 
place asserted." (Olbers, in Sebum., Jahrb., 1837, p. 52-58; and in 
Vol. I.— F 



12*2 COSMOS. 

whose accidental coincidence could alone convert a possible 
into an actual fact. The view of the orighial existence of 

Gehlei-, NeuesPhyslk. Worterbuche, bd. yi., abth. 3, s. 2129-2130.)^ If 
we could assume volcanic forces to be still active on the Moon's surface, 
the absence of atmospheric resistance would certainly give to their 
projectile force an advantage over that of our terrestrial volcanoes ; but 
even in respect to the measure of the latter force (the projectile force 
of our own volcanoes), we have no observations on which any reliance 
can be placed, and it has probably been exceedingly overrated. Dr. 
Peters, who accurately observed and measured the phenomena present- 
ed by Mtna, found that the greatest velocity of any of the stones pro- ' 
jected from the crater was only 1250 feet to a second. Observations 
on the Peak of TenerifFe, in 1798, gave 3000 feet. Although Laplace, 
at the end of his work (Expos, du Syst. du Monde, ed. de 1824, p. 399).. 
cautiously observes, regarding aerolites, " that in all probability they 
come from the depths of space," yet we see from another passage 
(chap, vi., p. 233) that, being probably unacquainted with the extra- 
ordinary planetary velocity of meteoric stones, he inclines to the hy- 
pothesis of their lunar origin, always, however, assuming that the stones 
projected from the Moon " become satellites of our Earth, describing 
around it more or less eccentric orbits, and thus not reaching its atmos- 
phere until several or even many revolutions have been accomplished." 
As an Italian at Tortona had the fancy that aerolites came from the 
Moon, so some of the Greek philosophers thought they came from the 
Sun. This was the opinion of Diogenes Laertius (ii., 9) regarding the 
origin of the mass that fell at iEgos Potamos (see note, p. 116). Pliny, 
whose labors in recording the opinions and statements of preceding 
writei'S are astonishing, repeats the theoiy, and derides it the more 
freely, because he, with earlier writers (Diog. Laert., 3 and 5, p. 99, 
Hiibner), accuses Anaxagoras of having predicted the fall of aerolites 
from the Sun: "Celebrant Grseci Anaxagoram Clazomenium Olyra- 
piadis septuagesimae octavse secundo anno praedixisse caelestium littera- 
rum scientia, quibus diebus saxum casurum esse e sole, idque factum 
interdiu in Thracife parte ad iEgos flumen. Quod si quis prsedictum 
credat, simul fateatur necesse est, majoris miraculi divinitatem Anax- 
agorae faisse, solvique rerum naturae intellectum, et confundi omnia, si 
aut ipse Sol lapis esse aut unquam lapidem in eo fuisse credatur; de- 
cidere tamen crebro non erit dubium." The fall of a moderate-sized 
stone, which is pi'eserved in the Gymnasium at Abydos, is also report- 
ed to have been foretold by Anaxagoras. The fall of aerolites in bright 
sunshine, and when the Moon's disk was invisible, probably led to the 
idea of sun-stones. Moreovev, according to one of the physical dogmas 
of Anaxagoras,. which brought on him the persecution of the theologians 
(even as they have attacked the geologists of our own times), the Sun 
was regarded as " a molten fiery mass" (fivdpoc dtdTvvpo^). In accord- 
ance with these views of Anaxagoras, we find Euripides, in Phaeton, 
terming the Sun "a golden mass;" that is to say, a tire-colored, bright- 
ly-shining matter, but not leading to the inference that aerolites are 
golden suu-stones. (See note to page 115.) Compare Valckenaer, 
Diatribe in Eurip. perd. Dram. Reliqnias, 17G7, p. 30. Diog. Laert., 
ii., 40. Hence, among the Greek philosophers, we find four hypotheses 
regarding the origin of falling stars : a telluric origin from ascending 
exhalations; masses of stone raised by hurricane (see Aristot., il/e/'cor., 
lib. i., cap. iv., 2-13, and cap. vii., 9); a solar origin; and. lastly, an 



AEROLITES. 123 

Email planetary masses in space is simpler, and, at the same 
time, more analogous with those entertained concerning the 
formation of other portions of the solar system. 

It is very probable that a large number of these cosmical 
bodies traverse space undestroyed by the vicinity of our at- 
mosphere, and revolve round the Sun without experiencing 
any alteration but a slight increase in the eccentricity of their 
orbits, occasioned by the attraction of the Earth's mass. We 
may, consequently, suppose the possibility of these bodies re- 
maining invisible to us during many years and frequent revo- 
lutions. The supposed phenomenon of ascending shooting 
stars and fire-balls, which Chladni has unsuccessfully endeav- 
ored to explain on the hypothesis of the reflection of strongly 
compressed air, appears at first sight as the consequence of 
some unknown tangential force propelling bodies from the 
earth ; but Bessel has sho^\^l by theoretical deductions, con- 
firmed by Feldt's carefully-conducted calculations, that, owing 
to the absence of any proofs of the simultaneous occurrence 
of the observed disappearances, the assumption of an ascent 
of shooting stars was rendered wholly improbable, and inad- 
missible as a result of observation. *" The opinion advanced 
by Olbers that the explosion of shooting stars and ignited fire- 
balls not moving in straight lines may impel meteors upward 
in the manner of rockets, and influence the direction of their 
orbits, must be made the subject of future researches. 

Shooting stars fall either separately and in inconsiderable 
numbers, that is, sporadically, or in swarms of many thou- 

origin in the regions of space, as heavenly bodies which had long re- 
mained invisible. Respecting this last opinion, which is that of Diog- 
enes of Apollonia, and entirely accords with that of the px'esent day, 
see pages 124 and 125. It is worthy of remark, that in Syria, as I have 
been assured by a learned Orientalist, now resident at Smyrna, Andrea 
de Nericat, who instructed me in Persian, there is a popular belief that 
aerolites chiefly fall on clear moonlight nights. The ancients, on the 
contrary, especially looked for their fall during lunar eclipses. (See 
Pliny, xxxvii., 10, p. 164. Solinus, c. 37. Salm., Exerc, p. 531; and 
the passages collected by Ukert, in his Geogr. der Griechen nnd Romer, 
th. ii., 1, s. 131, note 14.) On the improbability that meteoric masses 
are formed from metal-dissolving gases, which, according to Fusiuieri, 
may exist in the highest strata of our atmosphere, and, previously dif- 
fused through an almost boundless space, may suddenly assume a solid 
condition, and on the penetration and misceability of gases, see my 
Relat. Hist., t. i., p. 525. 

* Bessel, in Schum., Astr. Nachr., 1839, No 380 und 381, s. 222 iind 
346. At the conclusion of the Memoir there is a comparison of the 
Sun's longitudes with the epochs of the November phenomeuou, from 
the period of the first observations in Cumana ia 1799. 



124 COS3IOS. 

sands. The latter, which are compared by Arabian authors 
to swarms of locusts, are periodic in their occurrence, and 
move in streams, generally in a parallel direction. Among 
periodic falls, the most celebrated are that known as the No- 
vember phenomenon, occurring from about the 12th to the 
14th of November, and that of the festival of St. Lawrence 
(the 10th of August), whose *' fiery tears" were noticed in 
former times in a church calendar of England, no less than 
in old traditionary legends, as a meteorological event of con- 
stant recurrence.* Notwithstanding the great quantity of 
shooting stars and fire-balls of the most various dimensions, 
which, according to Kloden, were seen to fall at Potsdam on 
the night between the 12th and 13th of November, 1822, 
and on the same night of the year in 1832 throughout the 
whole of Europe, from Portsmouth to Orenburg on the Ural 
River, and even in the southern hemisphere, as in the Isle of 
France, no attention was directed to the periodicity of the 
phenomenon, and no idea seems to have been entertained of 
the connection existing between the fall of shooting stars and 
the recurrence of certain days, until the prodigious swarm of 
shooting stars which occurred in North America between the 
12th and 13th of November, 1833, and was observed by 
Olmsted and Palmer. The stars fell, on this occasion, like 
flakes of snow, and it was calculated that at least 240,000 
had fallen during a period of nine hours. Palmer, of New 
Haven, Connecticut, was led, in consequence of this splendid 
phenomenon, to the recollection of the fall of meteoric stones 
in 1799, first described by EUicot and myself,! and which, by 

* Dr. Thomas Forster {The Pocket Encyclopedia of Natural Phe- 
nomena, 1827, p. 17) states that a manuscript is preserved in the libra- 
ry of Chi-ist's College, Cambridge,^ written in the tenth century by a 
monk, and entitled Ephemerides Rerum Naturalium, in which the nat- 
ural phenomena for each day of the year are inscribed, as, for instance, 
the first flowering of plants, the arrival of birds, &c. ; the 10th of Au- 
gust is distinguished by the word " meteorodes." It was this indica- 
tion, and the tradition of the fiery tears of St. Lawrence, that chiefly 
induced Dr. Forster to undertake his extremely zealous investigation 
of the August phenomena. (Quetelet, Correspond. Mathim., Serie III., 
t. i., 1837, p. 433.) 

+ Humb., Rel. Hist., t. i., p. 519-527. Ellicot, in the Transaction* 
of the American Society, 1804, vol. vi., p. 29. Arago makes the follow- 
ing observations in reference to the November phenomena: " We thus 
become more and more confirmed in the belief that there exists a zone 
composed of millions of small bodies, whose orbits cut the plane of the 

a [No such manuscript is at present known to exist in the Ubrary of that college. 
For this information I am indebted to the inquiries of Mr. Cory, of Pembroke Col- 
lege, the learned editor of Hieroglyphics of Horapollo Nilous, Greek and English, 
1840.]— rr. 



AEROLITES. 125 

a comparison of the facts I had adduced, showed that the 
phenomenon had been simultaneously seen in the New Conti- 
n«it, from the equator to New Herrnhut in Greenland (64^ 
14' north latitude), and between 46° and 82° longitude. 
The identity of the epochs was recognized with astonishment. 
The stream, which had been seen from Jamaica to Boston 
(40° 21' north latitude) to traverse the whole vault of heaven 
on the 12th and 13th of November, 1833, was again observed 
in the United States in 1834, on the night between the 13th 
and 14th of November, although on this latter occasion it 
showed itself with somewhat less intensity. In Europe the 
periodicity of the phenomenon has since been manifested with 
great regularity. 

Another and a like regularly recurring phenomenon is that 
noticed in the month of August, the meteoric stream of St. 
Lawrence, appearing between the 9th and 14th of August. 
Muschenbroek,* as early as in the middle of the last century, 
drew attention to the frequency of meteors in the month of 
August ; but their certain periodic return about the time of 
St. Lawrence's day was first shown by Quetelet, Olbers, and 
Benzenberg. We shall, no doubt, in time, discover other pe- 
riodically appearing streams,! probably about the 22d to the 

ecliptic at about the point which our Eai-th annually occupies between 
the 11th and 13th of November. It is a new planetary world begin- 
ning to be revealed to us." (Annuaire, 1836, p. 296.) 

* Compare Muschenbroek, Introd. ad Phil. Nat., 1762, t. ii., p. 1061 ; 
Howard, On the Climate of London, vol. ii., p. 23, observations of the 
year 1806 ; seven years, therefore, after the earhest observations of 
Brandes (Benzenberg, ilber Sternschnuppen, s. 240-244) ; the August 
observations of Thomas Forster, iu Quetelet, op. cit., p. 438-453 ; those 
of Adolph Erman, Boguslawski, and Kreil, in Sebum., Jahrb., 1838, s. 
317-330. Regarding the point of origin in Pei'seus, on the 10th of Au- 
gust, 1839, see the accurate measurements of Bessel and Erman (Schum., 
Astr. Nachr., No. 385 und 428) ; but on the 10th of August, 1837, the 
path does not appear to have been retrograde ; see Arago, in Comptes 
Rendus, 1837, t. ii., p. 183. 

t On the 25th of April, 1095, " innumerable eyes in France saw stars 
faUiug from heaven as thickly as hail" {rit grando, nisi lucerent, pro den- 
sitate putaretur ; Baldr., p. 88), and this occurrence was regarded by 
the Council of Clermont as indicative of the great movement in Chris- 
tendom. (Wilken, Gesch. der Kreuzzuge, bd. i., s. 75.) On the 25th 
of April, 1800, a great fall of stars was observed in Virginia and Mas 
sachusetts ; it v/as " a fire of rockets that lasted two hours." Arago 
was the first to call attention to this " trainee d'asteroTdes," as a recur- 
ring phenomenon. {Annuaire, 1836, p. 297.) The falls of aerolites in 
the beginning of the mouth of December are also deserving of notice. 
In reference to their- periodic recurrence as a meteoric stj-eam, we may 
mention the eai'ly observation of Brandes on the night of the 6th and 
7th of December, 1798 (when he counted 2000 falling stars), and very 



126 COSMOS. 

25tli of April, between the Gth and 12th of December-, and, 
to judge by the number of true falls of aerolites enumerated 
by Capocci, also between the 27th and 29th of November, or 
about the 1 7th of July. 

Although the phenomena hitherto observed appear to have 
been independent of the distance from the pole, the tempera- 
ture of the air, and other climatic relations, there is, however, 
one perhaps accidentally coincident phenomenon which must 
not be wholly disregarded. The Northern Light, the Aurora 
Borealis, was unusually brilliant on the occurrence of the 
splendid fall of meteors of the 12th and 13th November, 1833, 
described by Olmsted. It was also observed at Bremen in 
1838, where the periodic meteoric fall was, however, less re- 
markable than at Richmond, near London. I have mentioned 
in another work the singular fact observed by Admiral Wran- 
gel, and frequently confirmed to me by himself,*' that when he 

probably the enormous fall of aSrolites that occurred at the Rio Assu, 
near the village of Macao, in the !6razils, on the 11th of December, 1836. 
(Brandes, Unterhalt. fur Freunde der Physik, 1825, heft i., s. 65, and 
Comptes Rendus, t. v., p. 211.) Capocci, in the interval betvreen 1809 
and 1839, a space of thirty years, has discovered twelve authenticated 
cases of aerolites occurring betw^een the 27th and 29th of November, 
besides others on the 13th of November, the 10th of August, and the 
17th of July. (Comptes Rendus, t. xi., p. 357.) It is singular that in 
the portion of the Earth's path corresponding vv^ith the months of Jan- 
uary and February, and probably also with March, no periodic streams 
of falling stars or aerolites have as yet been noticed ; although, when 
in the South Sea in the year 1803, I observed on the 15th of March a 
remarkably large number of falling stars, and they were seen to fall as 
in a swarm in the city of Quito, shortly before the terrible earthquake 
of Riobamba on the 4th of Februaiy, 1797. From the phenomena hith- 
erto observed, the following epochs seem especially worthy of remark : 

22d to the 25th of April. 

17th of July (17th to the 26th of July ?). (Quet., Corr., 1837, p. 435.) 

10th of August. 

12th to the 14th of November. 

27th to the 29th of November. 

6th to the 12th of December. 

When we consider that the regions of space must be occupied by 
myriads of comets, we are led by analogy, notwithstanding the differ- 
ences existing between isolated comets and rings filled w^ith asteroids, 
to regard the frequency of these meteoric streams with less astonish- 
ment than the first consideration of the phenomenon would be likely 
to excite. 

* Ferd. v. Wrangle, Reise Idngs der Nordkuste von Sibirien in den 
Jahren, 1820-1824, th. ii., s. 259. Regarding the recurrence of the 
denser swarm of the November stream after an interval of thirty-three 
years, see Olbers, in Jahrb., 1837, s. 280. I was infonmed in Cumana 
that shortly before the fearful earthquake of 1766, and consequently 
thirty-three years (the same interval) before the great fall of stars on 



AERULITKS. 1 il 

was on the Siberian coast of the Polar Sea, he observed, during 
an Aurora BoreaHs, certain portions of the vault of heaven, 
which were not illuminated, light up and continue luminous 
whenever a shooting star passed over them. 

The different meteoric streams, each of which is composed 
of myriads of small cosmical bodies, probably intersect our 
Earth's orbit in the same manner as Biela's comet. Accord- 
ing to this hypothesis, we may represent to ourselves these 
asteroid-meteors as composing a closed ring or zone, within 
which they all pursue one common orbit. The smaller plan- 
ets between Mars and Jupiter present us, if we except Pallas, 
with an analogous relation in their constantly intersecting 
orbits. As yet, however, we have no certain knowledge as 
to whether changes in the periods at which the stream be- 
comes visible, or the retardatio7is of the phenomena of which 
I hav^e already spoken, indicate a regular precession or oscilla.- 
tion of the nodes — that is to say, of the points of intersection 
of the Earth's orbit and of that of the ring ; or whether this 
rinsf or zone attains so considerable a degree of breadth from 
the irregular grouping and distances apart of the small bodies, 
that it requires several days for the Earth to traverse it. The 
system of Saturn's satellites shows us likewise a group of im- 
mense width, composed of most intimately-connected cosmical 
bodies. In this system, the orbit of the outermost (the seventh) 
satellite has such a vast diameter, that the Earth, in her rev- 
olution round the Sun, requires three days to traverse an ex- 
tent of space equal to this diameter. If, therefore, in one of 
these rings, which we regard as the orbit of a periodical 
stream, the asteroids should be so irregularly distributed as to 
consist of but few groups sufficiently dense to give rise to 
these phenomena, we may easily understand why we so sel- 
dom witness such glorious spectacles as those exhibited in the 
November months of 1799 and 1833. The acute mind of 
Olbers led him almost to predict that the next appearance 
of the phenomenon of shooting stars and fire-balls intermixed, 
falling like flakes of snow, would not recur until between the 
12th and 14th of November, 1867. 

the 11th and 12tli of November, 1799, a similar fiery mauif'estalioii had 
been observed in the heavens. But it was on the 21st of October, 1766, 
and not in the beginning of November, that the earthquake occurred. 
Possibly some traveler in Quito may yet be able to ascertain the day 
on which the volcano of Cayambe, which is situated there, was for the 
6j)ace of an hour enveloped in falling slars, so tlmt the inhabitants en- 
deavored to appease heaven by religious processions. {Eelat. Hist., 
I' \., ciiap. i\'., p .307 ; chap, x., j). .520 and 527.) 



128 COSMOS. 

The stream of the November asteroids has occasionally 
only been visible in a small section of the Earth. Thus, for 
instance, a very splendid meteoric shoiver vi^as seen in England 
in the year 1837, w^hile a most attentive and skillful observer 
at Braunsberg, in Prussia, only saw, on the same night, which 
was there uninterruptedly clear, a few sporadic shooting stars 
fall between seven o'clock in the evening and sunrise the next 
morning. Bessel* concluded from this " that a dense group 
of the bodies composing the great ring may have reached that 
part of the Earth in which England is situated, while the 
more eastern districts of the Earth might be passing at tht- 
time through a part of the meteoric ring proportionally lesi- 
densely studded with bodies." If the hypothesis of a regular 
progression or oscillation of the nodes should acquire greatei 
weight, special interest will be attached to the investigation 
0^ older observations. The Chinese annals, in which great 
falls of shooting stars, as well as the phenomena of comets, 
are recorded, go back beyond the age of Tyrtseus, or the sec- 
ond Messenian war. They give a description of two streams 
in the month of March, one of which is 687 years anterior to 
the Christian era. Edward Biot has observed that, among 
the fifty -two phenomena which he has collected from the 
Chinese annals, thosQ that were of most frequent recurrence 
are recorded at periods nearly corresponding with the 20th 
and 22d of July, O.S., and might consequently be identical 
with the stream of St. Lawrence's day, taking into account 
that it has advanced since the epochsf indicated. If the fall 
of shooting stars of the 21st of October, 1366, O.S. (a notice 
of which was found by the younger Von Boguslawski, in 
Benessius de Horowic's Ckronicon Ecclesice Pragensis), be 
identical with our November phenomenon, although the oc- 
currence in the fourteenth century was seen in broad day- 
light, we find by the precession in 477 years that this system 
of meteors, or, rather, its common center of gravity, must de- 

* From a letter to myself, dated Jan. 24th, 1838. The enormous 
swarm of falling stax's in November, 1799, was almost exclusively seen 
in America, where it was witnessed from New Herruhut in Greenland 
to the equator. The sw^ai'ms of 1831 and 1832 were visible only iu 
Europe, and those of 1833 and 1834 only in the United States of North 
America. 

t Lettre de M. Edouard Biot a M. Quetelet, sur les anciennes appari- 
tions d'Etoiles Filantes en Chine, in the Bull, de V Acadimie de Brux' 
elles, 1843, t. x., No. 7, p. 8. On the notice from the Ckronicon Ec- 
clesice Pragensis, see the younger Boguslawski, in Poggend., Annalert, 
bd. xlviii., s. 612. 



AEROLITES. ^ 129 

Bcribe a retrograde orbit round the Sun. It also follows, from 
the views thus developed, that the non-appearance, during 
certain years, in any portion of the Earth, of the two streams 
hitherto observed in November and about the time of St. 
Lawrence's day, must be ascribed either to an interruption in 
the meteoric ring, that is to say, to intervals occurring be- 
tween the asteroid groups, or, according to Poisson, to the ac- 
tion of the larger planets* on the form and position of thii 
annulus. 

The solid masses which are observed by night to fall to the 
earth from fire-balls, and by day, generally when the sky is 
clear, from a dark small cloud, are accompanied by much 
noise, and although heated, are not in an actual state of in- 
candescence. They undeniably exhibit a great degree of gen- 
eral identity with respect to their external form, the character 
of their crust, and the chemical composition of their principal 
constituents. These characteristics of identity have been ob- 
served at all the different epochs and in the most various parts 
of the earth in which these meteoric stones have been found. 
This striking and early-observed analogy of physiognomy in 
the denser meteoric masses is, however, met by many excep- 
tions regarding individual points. What differences, for in- 
stance, do we not find between the malleable masses of iron 
of Hradschina in the district of Agram, those from the shores 
of the Sisim in the government of Jeniseisk, rendered so cele- 
brated by Pallas, or those which I brought from Mexico,t all 
of which contain 96 per cent, of iron, from the aerolites of 
Siena, in which the iron scarcely amounts to 2 per cent., or 
the earthy aerolite of Alais (in the Department du Gard), 
which broke up in water, or, lastly, from those of Jonzac and 
Juvenas, which contained no metallic iron, but presented a 

* " It appears that an apparently inexhaustible number of bodies, too 
small to be observed, are moving in the regions of space, either around 
the Sun or the planets, or perhaps even around their satellites. It is 
supposed that when these bodies come in contact with our atmosphere, 
the difference between their velocity and that of our planet is so great, 
that the friction which they experience from their contact with the air 
heats them to incandescence, and sometimes causes their explosion. If 
the group of falling stars form an annulus around the Sun, its velocity 
of circulation may be very different from that of our Earth ; and the 
displacements it may experience in space, in consequence of the actions 
of the various planets, may render the phenomenon of its intersecting 
the planes of the ecliptic possible at some epochs, and altogether im« 
possible at others." — Poisson, Recherches sur la Probability des Juge- 
vients, p. 306, 307. 

t Humboldt, Essai Politique sur la Nmiv. Espagne (2de edit.), t. iii. 
p. 310. 

F 2 



130 COSMOS. 

mixture of oryctognostically distinct crystalline components ! 
These differences have led mineralogists to separate these cos- 
mical masses into two classes, namely, those containing nick 
elliferous meteoric iron, and those consisting of fine or coarse- 
ly-granular meteoric dust. The crust or rind of aerolites is 
peculiarly characteristic of these bodies, being only a few 
tenths of a line in thickness, often glossy and pitch-like, and 
occasionally veined.* There is only one instance on record, 
as far as I am aware (the aerolite of Chantonnay, in La Ven- 
dee), in which the rind was absent, and this meteor, like that 
of Juvenas, presented likewise the peculiarity of having pores 
and vesicular cavities. In all other cases the black crust is 
divided from the inner light-gray mass by as sharply-defined 
a line of separation as is the black leaden-colored investment 
of the white granite blockst which I brought from the cata- 
racts of the Orinoco, and which are also associated with 
many other cataracts, as, for instance, those of the Nile and 
of the Congo River. The greatest heat employed in our 
porcelain ovens would be insufficient to produce any thing 
similar to the crust of meteoric stones, whose interior re- 
mains wholly unchanged. Here and there, facts have been 
observed which would seem to indicate a fusion together of 
the meteoric fragments ; but, in general, the character of the 
aggregate mass, the absence of compression by the fall, and 
the inconsiderable degree of heat possessed by these bodies 
when they reach the earth, are all opposed to the hypothesis 
of the interior being in a state of fusion during their short 
passage from the boundary of the atmosphere to our Earth. 

The chemical elements of which these meteoric masses 
consist, and on which Berzelius has thrown so much light, 
are the same as those distributed throughout the earth's 
crust, and are fifteen in number, namely, iron, nickel, cobalt, 
manganese, chromium, copper, arsenic, zinc, potash, soda, sul- 
phur, phosphorus, and carbon, constituting altogether nearly 
one third of all the known simple bodies. Notwithstanding 
this similarity with the primary elements into which inorganic 
bodies are chemically reducible, the aspect of aerolites, owing 
to the mode in which their constituent parts are compounded, 
presents, generally, some features foreign to our telluric rocks 
and minerals. The pure native iron, which is almost always 

* The peculiar color of their crust was observed even as' early as ia 
the time of Pliny (ii., 56 and 58): "colore adusto." The phrase "lateri- 
bus pluisse" seems also to refer to the burned outer surface of aerolites. 

t Humb., Rel. Hist., t. ii., chap, xx., p. 299-302. 



AEROLITES. 131 

found incorporated with aerolites, imparts to them a pecul- 
iar, but not, consequently, a s,elenic character ; for in other 
regions of space, and in other cosmical hodies besides our Moon, 
water may be wholly absent, and processes of oxydation of 
rare occurrence. 

Cosmical gelatinous vesicles, similar to the organic nostoc 
(masses which have been supposed since the Middle Ages to 
be connected with shooting stars), and those pyrites of Sterli 
tamak, west of the Uralian Mountains, which are said to have 
constituted the interior of hailstones,* must both be classed 
among the mythical fables of raeteorolog}^ Some few aero- 
lites, as those composed of a finely granular tissue of olivine, 
augite, and labradorite blended together! (as the meteoric stone 
found at Juvenas, in the Department de I'Ardeche, which re- 
sembled dolorite), are the only ones, as Gustav Rose has 
remarked, which have a more familiar aspect. These bodies 
contain, for instance, crystalline substances, perfectly similar 
to those of our earth's crust ; and in the Siberian mass of 
meteoric iron investigated by Pallas, the olivine only differs 
from common olivine by the absence of nickel, which is re- 
placed by oxyd of tin.:t As meteoric olivine, like our basalt, 
contains from 47b to 49 per cent, of magnesia, constituting, 
according to Berzelius, almost the half of the earthy compo- 
nents of meteoric stones, we can not be surprised at the great 
quantity of silicate of magnesia found in these cosmical bodies. 
If the aerolite of Juvenas contain separable crystals of augite 
and labradorite, the numerical relation of the constituents 

* Gustav Rose, Reise nach dem Ural, bd. ii., s. 202. 

t Gustav Rose, in Poggend., Ann., 1825, bd. iv., s. 173-192. Ram- 
melsberg, Erstes Suppl. zum chem. Handworterbuche der Mineralogie, 
1843, s. 102. "It is," says the clear-minded obsex-ver Olbei's, '"a re- 
markable but hitherto uni-egarded fact, that while shells are found in 
secondary and tertiaiy formations, no fossil meteoric stones have as yet 
been discovered. May we conclude from this circumstance that pre- 
vious to the present and last modification of the earth's surface no me- 
teoric stones fell on it, although at the present time it appears probable, 
from the researches of Schreibers, that 700 fall annually?" (Olbers, 
in Schum., Jahrb., 1838, s. 329.) Problematical nickelliferous masses 
of native iron have been found in Northern Asia (at the gold-washing 
establishment at Petropawlowsk, eighty miles southeast of Kusnezk), 
imbedded thirty -one feet in the ground, and more recently in the West- 
ern Carpathians (the mountain chain of Magura, at Szlanicz), both of 
which are remarkably like meteoric stones. Compare Erman. Arckiv 
fur wissenschaftliche Kundevon Russland, hd. i., s. 315, and Haidhiger, 
Bericht uher Szlaniczer Schurfe in Ungarn. 

X Berzelins, Jahresber., bd. xv., s. 217 und 231. Rammelsberg, 
Handtcdrterb., abth. ii., s. 2.5-28. 



132 COSMOS. 

render it at least probable tbat the meteoric masses of Cha- 
teau-Ren ard may be a compound of diorite, consisting of horn- 
blende and albite, and those of Blansko and Chantonnay com- 
pounds of hornblende and labradorite. The proofs of the tel- 
luric and atmospheric origin of aerolites, which it is attempt- 
ed to base upon the oryctognostic analogies presented by these 
bodies, do not appear to me to possess any great weight. 

Recallins: to mind the remarkable interview between New- 
ton and Conduit at Kensington,* I would ask why the ele- 
mentary substances that compose one group of cosmical bodies, 
or one planetary system, may not, in a great measure, be iden- 
tical ? Why should we not adopt this view, since we may 
conjecture that these planetary bodies, like all the larger or 
smaller agglomerated masses revolving round the sun, have 
been thrown ofi^ from the once far more expanded solar at- 
mosphere, and been formed from vaporous rings describing 
their orbits round the central body ? We are not, it appears 
to me, more justified in applying the term telluric to the nickel 
and iron, the olivine and pyroxene (augite), found in meteoric 
stones, than in indicating the German plants Avhich I found 
beyond the Obi as European species of the flora of Northern 
Asia. If the elementary substances composing a group of 
cosmical bodies of different magnitudes be identical, why 
should they not likewise, in obeying the laws of mutual at- 
traction, blend together under definite relations of mixture, 
composing the white glittering snow and ice in the polar zones 
of the planet Mars, or constituting in the smaller cosmical 
masses mineral bodies inclosing crystals of olivine, augite, and 
labradorite ? Even in the domain of pure conjecture we should 
not suffer ourselves to be led away by unphilosophical and ar- 
bitrary views devoid of the support of inductive reasoning. 

Remarkable obscurations of the sun's disk, during whicli 
the stars have been seen at mid-day (as, for instance, in the 
obscuration of 1547, which continued for three days, and oc- 
curred about^ the time of the eventful battle of Miihlberg), 
can not be explained as arising from volcanic ashes or mists, 
and were regarded by Kepler as owing either to a materia 
cometica, or to a black cloud formed by the sooty exhalations 
of the solar body. The shorter obscurations of 1090 and 
1203, which continued, the one only three, and the other six 

* " Sir Isaac Newton said he took all the planets to be composed of 
the same matter with the Earth, viz., earth, water, and stone, but vari- 
ously concocted." — Turner, Collections for the History of Grantham^ 
eontainhig authentic Memoirs of Sir Isaac Newton, p. 172. 



AEROLITES. 133 

hours, were supposed by Chiadni and Schnurrer to be occa 
sioned by the passage of meteoric masses before the sun's disk. 
Since the period that streams of meteoric shootmg stars were 
first considered with reference to the direction of their orbit 
as a closed ring, the epochs of these mysterious celestial phe- 
nomena have been observed to present a remarkable connec 
tion with the regular recurrence of swarms of shooting stars 
Adolph Erman has evinced great acuteness of mind in his ac- 
curate investiofation of the facts hitherto observed on this sub- 
ject, and his researches have enabled him to discover the con- 
nection of the sun's conjunction with the August asteroids on 
the 7th of February, and with the November asteroids on the 
12th of May, the latter period corresponding with the days 
of St. Mamert (May 11th), St. Pancras (May 12th), and St. 
Servatius (May 13th), which, according to popular belief, 
were accounted " cold days."^ 

The Greek natural philosophers, who were but little dis 
posed to pursue observations, but evinced inexhaustible fer 
tility of imagination in giving the most various interpretation 
of half-perceived facts, have, however, left some hypotheses 
reofardinor shooting stars and meteoric stones which strikingly 
accord with the views now almost universally admitted of 
the cosmical process of these phenomena. " Falling stars," 
says Plutarch, in his life of Lysander,t " are, according to 

* Adolph Erman, in Poggend., Annalen, 1839, bd. xlviii., s. 582- 
601. Biot had preNaously thrown doubt regarding the probability of 
the November stream reappearing in the beginning of May (Comptes 
Rendns, 1836, t. ii., p. 670). Madler has examined the mean depres- 
sion of temperature on the three ill-named days of May by Berlin ob- 
servations for eighty-six years ( Verhandl. des Vereins zur Befurd. des 
Gartenbaues, 183"4, s. 377), and found a retrogression of temperature 
amounting to 20-2 Fahr. from the 11th to the 13th of May, a period at 
wliich nearly the most rapid advance of heat takes place. It is much 
to be desired that this phenomenon of depressed temperature, which 
some have felt inclined to attribute to the melting of the ice in the 
northeast of Europe, should be also investigated in very remote spots, 
as in America, or i*i the southern hemisphere. (Comp. Bull, de VAcad. 
Imp. de Si. Petershourg, 1843, t. i.. No. 4.) 

t Plut., Vitce par. in Lysandro, cap. 22. The statement of Dama- 
cho9 (Daimachos), that for seventy days continuously there was a fiery 
cloud seen in the sky, emitting sparks like falling stars, and which then, 
sinkii^g nearer to the earth, let fall the stone of iEgos Potamos, " which, 
however, was only a small pai't of it," is extremely improbable, since 
the direction and velocity of the fire-cloud would in that case of neces- 
sity have to remain for so many days the same as those of the earth ; 
and this, in the fire-ball of the 19th of July, 1686, described by Halley 
( Trans., vol. xxix., p. 163), lasted only a few minutes. It is not alto- 
gether certain whether Daimachos, the writer, -Kepi evaef'ELag, was the 



134 coSiMos. 

k 
f 

the opinion of some physicists, not eruptions of the ethereal 
fire extinguished in the air immediately after its ignition, nor 
yet an inflammatory combustion of the air, which is dissolved 
in large quantities in the upper regions of space, but these 
meteors are rather a fall of celestial bodies, which, in conse- 
quence of a certain intermission in the rotatory force, and by 
the impulse of some irregular movement, have been hurled 
down not only to the inhabited portions of the Earth, but 
also beyond it into the great ocean, where we can not find 
them." Diogenes of Apollonia^ expresses himself still more 
explicitly. According to his views, " Stars that are invisible, 
and, consequently, have no name, move in space together with 
those that are visible. These invisible stars frequently fall 
to the earth and are extinguished, as the stony star which fell 
burning at -^gos Potamos." The Apollonian, who held all 
other stellar bodies, when luminous, to be of a pumice-like 
nature, probably grounded his opinions regarding shooting 
stars and meteoric masses on the doctrine of Anaxagoras the 
Clazomenian, who regarded all the bodies in the universe 
" as fragments of rocks, which the fiery ether, in the force 
of its gyratory motion, had torn from the Earth and con- 
verted into stars." In the Ionian school, therefore, according 
to the testimony transmitted to us in the views of Diogenes 
of Apollonia, aerolites and stars were ranged in one and the 
same class ; both, when considered with reference to their 
primary origin, being equally telluric, this being understood 
only so far as the Earth was then regarded as a central body,t 

same person as Daimachos of Platjea, who was sent by Seleucus to 
India to the sou of Androcottos, and who was charged by Strabo with 
being " a speaker of lies" (p. 70, Casaub.). From another passage of 
Plutarch {Compar. Solonis c. Cop., cap. 5) we should almost believe 
that he was. At all events, we have here only the evidence of a very 
late author, who wrote a century and a half after the fall of aerolites 
occurred in Thrace, and whose authenticity is also doubted by Plutarch. 

■* Stob., ed. Heeren, i., 25, p. 508 ; Plut., de plac. Philos., ii., 13. 

t The remarkable passage in Plut., deplac. Philos., ii., 13, runs thus: 
'' Anaxagoras teaches that the surrounding ether is a fiery substance, 
which, by the power of its rotation, tears rocks from the earth, inflames 
tliem, and converts them into stars." Applying an ancient fable to il- 
lustrate a physical dogma, the Clazomenian appears to have ascribed 
the fall of the Nemtean Lion to the Peloponnesus from the Moon to 
such a rotatory or centrifugal force, (^lian., xii., 7; Pint., de 'Facie 
in Orbe Lunce, c. 24; Schol. ex Cod. Paris., in ApoU. Argon., lib. i., 
p. 498, ed. Schaef., t. ii., p. 40; Meineke, Annal. Alex., 1843, p. 85.) 
Here, instead of stones from the Moon, we have an niiimal from the 
Moon! According to an acute remark of Bockh, the ancient mythol- 
ogy of the Nerasean lunar lion has an astronomical origin, tind is sym- 



AEROLITES. 135 

foiming all things around it in the same manner as we, ac- 
cording to our present views, suppose the planets of our sys- 
tem to have originated in the expanded atmosphere of anoth- 
er central body, the Suri. These views must not, therefore, 
be confounded with what is commonly termed the telluric or 
atmospheric origin of meteoric stones, nor yet with the singu- 
lar opinion of Aristotle, which supposed the enorn:v)us mass 
of iEgos Potamos to have been raised by a hurricane. That 
arrogant spirit of incredulity, which rejects facts without at- 
tempting to investigate them, is in some cases almost more 
injurious than an unquestioning credulity. Both are alike 
detrimental to the force of investigfation. Notwithstandinsr 
that for more than two thousand years the annals of different 
nations had recorded falls of meteoric stones, many of which 
had been attested beyond all doubt by the evidence of irre- 
proachable eye-witnesses — notwithstanding the important part 
enacted by the Baetylia in the meteor- worship of the ancients 
— notwithstanding the fact of the companions of Cortez hav- 
ing seen an aerolite at Cholula which had fallen on the neigh- 
boring pyramid — notwithstanding that califs and Mongolian 
chiefs had caused swords to be forged from recently-fallen 
meteoric stones — nay, notwithstanding that several persons 
had been struck dead by stones falling from heaven, as, for 
instance, a monk at Crema on the 4th of September, 1511, 
another monk at Milan in 1650, and two Swedish sailors on 
board ship in 1674, yet this great cosmical phenomenon re- 
mained almost wholly unheeded, and its intimate connection 
with other planetary systems unknown, until attention was 
drawn to the subject by Chladni, who had already gained im- 
mortal renown by his discovery of the sound-figures. He who 
is penetrated with a sense of this mysterious connection, and 
whose mind is open to deep impressions of nature, will feel 
himself moved by the deepest and most solemn emotion at 
the sight of every star that shoots across the vault of heaven, 
no less than at the glorious spectacle of meteoric swarms in 
the November phenomenon or on St. Lawrence's day. Here 
motion is suddenly revealed in the midst of nocturnal rest. 
The still radiance of the vault of heaven is for a moment an- 
imated with life and movement. In the mild radiance left 
on the track of the shooting star, imagination pictures the 
lengthened path of the meteor through the vault of heaven, 

bolically connected in chronology with the cycle of intercalation of the 
lunar year, with the moon- worship at Nemiea, and the games by which 
it was acc(impanied. 



136 COSMOS. 

while, every where around, the luminous asteroids proclaim 
the existence of one common material universe. 

If we compare the volume of the innermost of Saturn's sat- 
ellites, or that of Ceres, with the immense volume of the Sun, 
all relations of magnitude vanish from our minds. The ex- 
tinction of suddenly resplendent stars in Cassiopeia, Cygnus, 
and Serpentarius have already led to the assumption of other 
and non-luminous cosmical bodies. We now know that the 
meteoric asteroids, spherically agglomerated into small masses, 
revolve round the Sun, intersect, like comets, the orbits of the 
luminous larger planets, and become ignited either in the vi- 
cinity of our atmosphere or in. its upper strata. 

The only media by which we are brought in connection 
with other planetary bodies, and with all portions of the uni- 
verse beyond our atmosphere, are light and heat (the latter 
of which can scarcely be separated from the former),* and 
those mysterious powers of attraction exercised by remote 
masses, according to the quantity of their constituents, upon 
our globe, the ocean, and the strata of our atmosphere. An- 
other and different kind of cosmical, or, rather, material mode 
of contact is, however, opened to us, if we admit falling stars 
and meteoric stones to be planetary asteroids. They not only 
act upon us merely from a distance by the excitement of lumin- 
ous or calorific vibrations, or in obedience to the laws of mu- 
tual attraction, but they acquire an actual material existence 
for us, reaching our atmosphere from the remoter regions of 
universal space, and remaining on the earth itself Meteoric 
stones are the only means by which we can be brought in pos- 
sible contact with that which is foreign to our own planet. 
Accustomed to gain our knowledge of what is not telluric 
solely through measurement, calculations, and the deductions 
of reason, we experience a sentiment of astonishment at find- 
ing that we may examine, weigh, and analyze bodies that ap- 

* The following remarkable passage on the radiation of heat from 
the fixed stars, and on their low combustion arid vitality — one of Kep- 
ler's many aspirations — occurs in the Paralipom. in Vitell. Astron. para 
Optica, 1604, Propos. xxxii., p. 25 : " Lucis proprium est calor, sydera 
omnia calefaciunt. De syderum luce claritatis ratio testatur, calorem 
universorum in minori esse proportione ad calorem unius solis, quam 
ut ab homine, cujus est certa caloris meusura, uterquo simul percipi et 
judicari possit. De cincindularum lucula tenuissima negare non potes, 
quin cum calore sit. Vivunt enim et moventur, hoc autem non sine 
calefactione perficitur. Sic neque putrescentium lignorum lux sno ca« 
lore destituitur ; nam ipsa puetredo quidam lentus ignis est. Inest et 
stirpibus suus calor." (Compare Kepler, Epit. Astron. Copernicance, 
1618, t. i., lib. i., p. 35.) 



ZODIACAL LIGHT. 137 

pertain to the outer world. This awakens, by the power of 
the imagination, a meditative, spiritual train of thought, where 
the untutored mind perceives only scintillations of light in the 
firmament, and sees in the blackened stone that falls from the 
exploded cloud nothing beyond the rough product of a power- 
ful natural force. 

Although the asteroid-swarms, on which we have been led, 
from special predilection, to dwell somewhat at length, ap- 
proximate to a certain degree, in their inconsiderable mass 
and the diversity of their orbits, to comets, they present this 
essential difference from the latter bodies, that our knowledge 
of their existence is almost entirely limited to the moment of 
their destruction, that is, to the period when, drawn within 
the sphere of the Earth's attraction, they become luminous 
and ignite. 

In order to complete our view of all that we have learned 
to consider as appertaining to our solar system, which now, 
since the discovery of the small planets, of the interior comets 
of short revolutions, and of the meteoric asteroids, is so rich 
and complicated in its form, it remains for us to speak of the 
ring of zodiacal light, to which we have already alluded. 
Those who have lived for many years in the zone of palms 
must retain a pleasing impression of the mild radiance with 
which the zodiacal light, shooting pyramidally upward, illu- 
mines a part of the uniform length of tropical nights. I have 
seen it shine with 9.n intensity of hglit equal to the milky way 
in Sagittarius, and that not only in the rare and dry atmos- 
phere of the summits of the Andes, at an elevation of from 
thirteen to fifteen thousand feet, but even on the boundless 
grassy plains, the llanos of Venezuela, and on the sea-shore, 
beneath the ever-clear sky of Cumana. This phenomenon 
was often rendered especially beautiful by the passage of light, 
fleecy clouds, which stood out in picturesque and bold relief 
from the luminous back-ground. A notice of this aerial spec- 
tacle is contained in a passage in my journal, while I was on 
the voyage from Lima to the western coasts of Mexico : " For 
three or four nights (between 10^ a,nd 14° north latitude) the 
zodiacal light has appeared in greater splendor than I have 
ever observed it. The transparency of the atmosphere must 
be remarkably great in this part of the Southern Ocean, to 
judge by the radiance of the stars and nebulous spots. From 
the 14th to the 19th of March a regular interval of three 
quarters of an hour occurred between the disappearance of the 
sun's disk in the ocean and the first manifestation of the zodi- 



138 COSMOS. 

acal light, although the night was already perlectly dark. An 
hour after sunset it was seen in great brilUancy between Alde- 
baran and the Pleiades ; and on the 18th of March it attained 
an altitude of 39^ 5'. Narrow elongated clouds are scattered 
over the beautiful deep azure of the distant horizon, flitting 
past the zodiacal light as before a golden curtain. Above 
these, other clouds are from time to time reflecting the most 
brightly variegated colors. It seems a second sunset. On 
this side of the vault of heaven the lightness of the night ap- 
pears to increase almost as much as at the first quarter of the 
moon. Toward 10 o'clock the zodiacal light generally becomes 
very faint in this part of the Southern Ocean, and at midnight 
I have scarcely been able to trace a vestige of it. On the 16th 
of March, when most strongly luminous, a faint reflection was 
visible in the east." In our gloomy so-called " temperate" 
northern zone, the zodiacal light is only distinctly visible in 
the beginning of Spring, after the evening twilight, in the 
western part of the sky, and at the close of Autumn, before 
the dawn of day, above the eastern horizon. 

It is difficult to understand how so striking a natural phe- 
nomenon should have failed to attract the attention of physi- 
cists and astronomers until the middle of the seventeenth cen- 
tury, or how it could have escaped the observation of the Ara- 
bian natural philosophers in ancient Bactria, on the Euphra- 
tes, and in the south of Spain. Almost equal surprise is ex- 
cited by th^ tardiness of observation of the nebulous spots in 
Andromeda and Orion, first described by Simon Marius and 
Huygens. The earliest explicit description of the zodiacal 
fight occurs in Childrey's Britannia Baconica* in the year 

* " There is another thing which I recommend to the observation 
of mathematical men, which is, that in February, and for a fittle before 
and a Httle after that month (as I have observed several years together), 
about six in the evening, when the twilight hath almost deserted the 
horizon, you shall see a plainly discernible way of the twilight striking 
up towai-d the Pleiades, and seeming almost to touch them. It is so 
observed any clear night, but it is best iliac nocte. There is no such 
way to be observed at any other time of the year (that I can perceive), 
nor any other way at that time to be perceived darting up elsewhere ; 
and I believe it hath been, and will be constantly visible at that time 
S)f the year; but what the cause of it in nature should be, I can not yet 
imagine, but leave it to future inquiry." (Childrey, Britannia Baco- 
nica, 1661, p. 183.) This is the first view and a simple description of 
the phenomenon. (Cassini, Dicouverte de la Lumiere Cileste qui pa- 
roit dans le Zodiaque, in the M&m. de VAcad., t. viii., 1730, p. 276. 
Mairan, TraiU Phys. de V Aurore Boriale, 1754, p. 16.) In this remark- 
able work by Childrey there are to be found (p. 9 1) very clear accounts 
of the epochs of maxima and minima diurnal and annual temperatures. 

I 



zoiJiATAL i.i(;in'. 139 

IGCl. Tlie first observation of the phenomenon may have 
been made two or three years prior to this period ; but, not- 
withstanding, the merit oi" having (in the spring of 1683) been 
the first to investigate the phenomenon in all its relations in 
space is incontestably due to Dominicus Cassini. The light 
whii^h he saw at Bologna in 1668, and wliich was observed 
at the same time in Persia by the celebrated traveler Char- 
din (the court astrologers of Ispahan called this light, which 
had never before been observed, nijzek, a small lance), was 
not the zodiacal light, as has often been asserted,* but the 

and of the retardation of the extremes of the effects in meteorological 
processes. It is, howevei", to be regretted that our Baconian-philosophy- 
loving author, who was Lord Henry Somerset's chaplain, lell into the 
same error as Bernardin de St. Pierre, and regarded the Earth as elon- 
gated at the poles (see p. 148). At the first, he believes that the Earth 
was spherical, but supposes tliat the uninterrupted and inci'easing addi- 
tion of layers of-ice at both poles has changed its figure ; and that, as the 
ice is formed from water, the quantify of that hquid is every where 
diminishing. 

* Dominicus Cassini {Man. de VAcad., t. viii., 1730, p. 188), and 
Mairaii {Aurore Bor., p. 16), have even maintained that the phenome- 
non observed in Persia in 16G8 was the zodiacal light. Delambre 
{Hist, de V Astron. Moderne, t. ii., p. 742), in very decided terms, ascribes 
the discovery of this light to the celebrated traveler Chardin ; but in the 
C our 07171 ement de Soliman, and in several passages of the narrative of his 
travels (ed. de Langles, t. iv., p. 326; t. x., p. 97), he only applies the 
term niazouk (nyzek), or "petite lance," to " tiie great and famous 
comet which appeared over neai'ly the whole world in 1668, and whose 
head was so hidden in the w^est that it could not be perceived in the 
horizon of Ispahan" {Atlas du Voyage de Chardin, Tab. iv. ; froin the 
observations at Schiraz). The head or nucleus of the comet was, how- 
ever, visible in the Brazils and in India (Pingie, Cometog7-., t. ii., p. 22). 
Regardhig the conjectured identity of the last great comet of March, 
1843, with this, which Cassini mistook for the zodiacal light, see Schuin., 
Astr. Nachr., 1843, No. 476 and 480. In Persian, the term "nizehi 
alteschin" (fiery spears or lances) is also applied to the rays of the ris- 
ing or setting sun, in the same way as " nayazik," according to Frey- 
tag's Arabic Lexicon, signifies " Stella) cadentes." The comparison of 
comets to lances and swords was, however, in the Middle Ages, ve;y 
common in all languages. The great comet of 1500, which was visible 
from April to June^ was always termed by the Italian writers of tliat 
time il Signor Astone (see my Exa77ien Critique de V Hist, de la Geo- 
graphic, t. v., p. 80). All the hypotheses that have been advanced to 
show that Descartes (Cassini, p. 230 ; Mairan, p. 16), and even Kepler 
(Delambre, t. i., p. 601), were acquainted with the zodiacal light, ap-. 
pear to me altogether untenable. Descartes {Principes, iii., art. 136, 
137) is very obscure in his remarks on comets, observing that their 
tails are formed " by oblique I'ays, which, falling on different parts of 
the planetary orbs, strike the eye laterally by extraordinaiy refraction," 
and that they might be seen morning and evening, "like a long beam," 
when the Sun is between the comet and the Earth. This passage no 
more refers to the zodiacal light than those in which Kepler {Epit. As 



140 COSMOS. 

enormous tail of a comet, whose head was concealed in the 
vapory mist of the horizon, and which, from its length and 
appearance, presented much similarity to the great comet of 
1843. We may conjecture, with much probability, that the 
remarkable light on the elevated plains of Mexico, seen for 
forty nights consecutively in 1509, and observed in the eastern 
horizon rising pyramidally from the earth, was the zodiacal 
light. I found a notice of this phenomenon in an ancient Az- 
tec MS., the Codex Telleriano-Reinensis* preserved in the 
Royal Library at Paris. 

This phenomenon, whose primordial antiquity can scarcely 
be doubted, and which was first noticed in Europe by Childrey 
and Dominicus Cassini, is not the luminous solar atmosphere 
itself, since this can not, in accordance with mechanical laws, 
be more compressed than in the relation of 2 to 3, and conse- 
quently can not be diffused beyond g^ths of Mercury's helio- 
centric distance. These same laws teach us that the altitude 
of the extreme boundaries of the atmosphere of a cosmical 

tron. Copernicance, t. i., p. 57, and t. ii., p. 893) speaks of the existence 
of a solar atmosphere (limbus circa solem, coma lucida), which, in 
eclipses of the Sun, prevents it ''from being quite night;" and even 
more uncertain, or indeed erroneous, is the assumption that the " trabes 
quas 6oKovg vocant" (Plin., ii., 2G and 27) had reference to the tongue- 
shaped rising zodiacal light, as Cassini (p. 231, art. xxxi.) and Mairan 
(p. 15) have maintained. Everywhere among the ancients the trabes 
are associated with the bolides (ardores et faces) and other fiery mete- 
ors, and even with long-barbed comets. ( Regarding doKog, doKiag, 
doKLTijg, see Schafer, Schol. Par. ad Apoll. Rhod., 1813, t. ii., p. 206; 
Pseudo-Aristot., de Mimdo, 2, 9 ; Comment. Alex. Joh. Philop. et Olymp. 
in Aristot. Meteor., lib. i., cap. vii., 3, p. 195, Ideler; Seneca, Nat. 
Quf£st., i., 1.) 

* Humboldt, Monumens des Peuples Indighies de V Amirique, t. ii.. 
p. 301. The rare manuscnpt which belonged to the Archbishop of 
Rheims, Le Tellier, contains various kinds of extracts from an Azt^ 
ritual, an astrological calendar, and historical annals, extending from 
1197 to 1549, and embx'aciug a notice of different natural phenomena, 
epochs of earthquakes and comets (as, for instance, those of 1490 and 
1529), and of (which are important in relation to Mexican chronology) 
solar eclipses. In Camargo's manusci-ipt Historia de Tlascala, the light 
rising in the east almost to the zenith is, singularly enough, described 
as " sparkling, and as if sown with stars." The description of this 
phenomenon, which lasted forty days, can not in any way apply to vol- 
canic eruptions of Popocatepetl, which lies very near, in tlie southeast- 
ern direction. (Prescott, History of the Conquest of Mexico, vol. i., p. 
284.) Later commentators have confounded this phenomenon, which 
Montezuma regarded as a warning of his misfortunes, with the " estrella 
que huraeava" (literally, which spring forth ; Mexican choloa, to leap or 
spring forth). With respect to the connection of this vapor with the 
star Citlal Choloha (Venus) and with " the mountain of the star" (Cit- 
laltepetl, the volcano of Orizaba), see my Monumens, t. ii., p. 303. 



ZODIACAL LIGHT. 141 

body above its equator, that is to say, the point at which 
gravity and centrifugal force are in equilibrium, must be the 
same as the altitude at which a sateUite would rotate round 
the central body simultaneously with the diurnal revolution 
of the latter.* This Umitation of the solar atmosphere in its 
present concentrated condition is especially remarkable when 
we compare the central body of our system with the nucleus 
of other nebulous stars. Herschel has discovered several, in 
which the radius of the nebulous matter surrounding the star 
appeared at an angle of 150". On the assumption that the 
parallax is not fully equal to 1", we find that the outermost 
nebulous layer of such a star must be 150 times further from 
the central body than our Earth is from the Sun. If, there- 
fore, the nebulous star were to occupy the place of our Sun, 
its atmosphere would not only include the orbit of Uranus, 
but even extend eight times beyond it.t 

Considering the narrow limitation of the Sun's atmosphere, 
which we have just described, we may with much probability 
regard the existence of a very compressed annulus of nebulous 
matter,| revolving freely in space between the orbits of Venus 
and Mars, as the material cause of the zodiacal light. As 

* Laplace, Expos, du Syst. du Monde, p. 270 ; M6canique C6leste, 
t. ii., p. 169 and 171; Schubert, Astr.,hd. iii., § 206. 

t Arago, in tlie Annuaire, 1842, p. 408. Compare Sir John Her- 
schel's considerations on the volume and faintness of li^ht of planetary 
nebulae, in Mary Somerville's Connection of the Physical Sciences, 1835, 
p. 108. The opinion that the Sun is a nebulous star, whose atmos- 
phere presents the phenomenon of zodiacal liglit, did not originate with 
Dominicus Cassini, but was first promulgated by Mairan in 1730 ( Traits 
de VAurore Bor., p. 47 and 263 ; Arago, in the Annuaire, 1842, p. 
412). It is a renewal of Kepler's views. 

X Dominicus Cassini was the first to assume, as did subsequently 
Laplace, Schubert, and Poisson, the hypothesis of a separate ring to 
explain the form of the zodiacal light. He says distinctly, " If the 
orbits of Mercury and Venus were visible (throughout their whole ex- 
tent), we should invariably observe them with the same figure and in 
the same position with regard to the Sun, and at the same time of the 
year with the zodiacal light." {Mim. de I' Acad., t. viii., 1730, p. 218, 
and Biot, in the Comptes Rendus, 1836, t. iii., p. 666.) Cassini be- 
lieved that the nebulous ring of zodiacal light consisted of innumerable 
small planetary bodies revolving round the Sun. He even went so 
far as to believe that the fall of fire-balls might be connected with the 
passage of the Earth through the zodiacal nebulous ring. Olmsted, 
and especially Biot (op. cit., p. 673), have attempted to establish its 
connection with the November phenomenon — a connection which 01 
bers doubts. (Schum., Jahrb., 1837, s. 281.) Regarding the question 
whether the place of the zodiacal light perfectly coincides with that 
of the Sun's equator, see Houzeau, in Schum., Astr. Nachr., 1843. No 
492, s. 190. 



142 COSMOS. 

yet we certainly know nothing definite regarding its actual 
material dimensions ; its augmentation* by emanations from 
the tails of myriads of comets that come within the Sun's 
vicinity; the singular changes affecting its expansion, since it 
sometimes does not appear to extend beyond our Earth's orbit ; 
or, lastly, regarding its conjectural intimate connection with 
the more condensed cosmical vapor in the vicinity of the Sun. 
The nebulous particles composing this ring, and revolving 
round the Sun in accordance with planetary laws, may either 
be self-luminous or receive light from that luminary. Even 
in the case of a terrestrial mist (and this fact is very remark- 
able), which occurred at the time of the new moon at mid- 
night in 1743, the phosphorescence was so intense that ob- 
jects could be distinctly recognized at a distance of more than 
600 feet. 

I have occasionally been astonished, in the tropical climates 
of South America, to observe the variable intensity of the 
zodiacal light. As I passed the nights, during many months, 
in the open air, on the shores of rivers and on llanos, I enjoy- 
ed ample opportunities of carefully examining this phenome- 
non. When the zodiacal light had been most intense, I have 
observed that it would be perceptibly weakened for a few 
minutes, until it again suddenly shone forth in full brilliancy. 
In some few instances I have thought that I could perceive — 
not exactly a reddish coloration, nor the lower portion darkened 
in an arc-like form, nor even a scintillation, as Mairan affirms 
he has observed — but a kind of flickering and wavering of 
the light.f Must we suppose that changes are actually in 
progress in the nebulous ring ] or is it not more probable that, 
although I could not, by my meteorological instruments, de- 
tect any change of heat or moisture near the ground, and 
small stars of the fifth and sixth magnitudes appeared to shine 
with equally undiminished intensity of light, processes of con- 
densation may be going on in the uppermost strata of the air, 
by means of which the transparency, or, rather, the reflection 
of light, may be modified in some peculiar and unknown man- 

* Sir John Herschel, Astron., ^ 487. 

t Arago, in the Annuaire, 1832, p. 246. Several physical facts ap 
pear to indicate that, in a mechanical separation of matter into its small- 
est particles, if the mass be very small in relation to the surface, the 
electrical tension may increase sufficiently for the production of light 
and heat. Experiments with a large concave miiTor have not hitherto 
given any positive evidence of the presence of radiant heat in the zo- 
diacal light. (Lettre de M. Matthiessen a M. Arago, in the Comptes 
Rendus, t. xvi., 1843, Avril, p. 687.) 



ZODIACAL LIGHT. 143 

ner ? An assumption of the existence of such meteorological 
causes on the confines of our atmosphere is strengthened by 
the " sudden flash and pulsation of light," which, according 
to the acute observations of Olbers, vibrated for several sec- 
onds through the tail of a comet, v/hich appeared during the 
continuance of the pulsations of light to be lengthened by sev- 
eral degrees, and then again contracted.* As, however, the 
separate particles of a comet's tail, measuring millions of miles, 

* "What you tell me of the changes of light in the zodiacal light, 
and of the causes to which you ascribe such changes within the trop- 
ics, is of the greater interest to me, since I have been for a long time 
past particularly attentive, every spring, to this phenomenon in our 
northern latitudes. I, too, have always believed that the zodiacal light 
I'otated ; but I assumed (contrary to Poisson's opinion, w^hich you have 
communicated to me) that it completely extended to the Sun, with 
considerably augmenting brightness. The light circle which, in total 
solar eclipses, is seen suiTOunding the darkened Sun, I have regarded 
as the brightest portion of the zodiacal light. I have convinced my 
self that this light is very different in different years, often for several 
successive years being very bright and diffused, while in other years 
it is scarcely perceptible. I think that I find the first trace of an allu- 
sion to the zodiacal light in a letter from Rothmann toTycho, in which 
he mentions that in spring he has observed the twilight did not close 
until the sun was 24*^ below the horizon. Rothmann must certainly 
have confounded the disappeai'ance of the setting zodiacal light in the 
vapors of the western horizon with the actual cessation of twilight. I 
have failed to observe the pulsations of the light, probably on account 
of the faintness with which it appears in these countries. You are, 
however, certainly right in ascribing those rapid vainalions in the light 
of the heavenly bodies, which you have perceived in tropical climates, 
to our own atmosphere, and especially to its higher regions. This is 
most strikingly seen in the tails of large comets. We often observe, 
especially in tlie clearest weather, that these tails exhibit pulsations, 
commencing from the head, as being the lowest part, and vibrating in 
one or two seconds tln-ough the entire tail, which thus appears rapidly 
to become some degrees longer, but again as rapidly contracts. That 
these undulations, which were formerly noticed with attention by 
Robert Hooke, and in more recent times by Schroter and Chladni, do 
not actnally occur in the tails of the comets, but are produced by our at- 
mosphere, is obvious when we recollect that the individual parts of 
those tails (which ai'e many millions of miles in length) lie at very dif- 
ferent distances from us, and that the light from their extreme points 
can only reach us at intervals of time which differ several minutes from 
one another. Whether what you saw on the Orinoco, not at intervals 
of seconds, but of minutes, were actual coruscations of the zodiacal 
light, or whether they belonged exclusively to the upper strata of our 
atmosphere, I will not attempt to decide ; neither can I explain the 
remarkable lightness of whole nights, nor the anomalous augmentation 
and prolongation of the twilight in the year 1831, particularly if, as has 
been remarked, the lightest part of these singular twilights did not coin- 
cide with the Sun's place below the horizon." (From a letter wr'tten 
by Dr. Olbers to myself, and dated Bremen, March 26th. 1833.) 



144 COSMOS. 

are verj' unequally distant from the earth, it is not possible, 
according to the laws of the velocity and transmission of light, 
that we should be able, in so short a period of time, to per- 
ceive any actual changes in. a cosmical body of such vast ex- 
tent. These considerations in no way exclude the reality of 
the change^ that have been observed in the emanations from 
the more condensed envelopes around the nucleus of a comet, 
nor that of the sudden irradiation of the zodiacal light from 
internal molecular motion, nor of the increased or diminished 
reflection of light in the cosmical vapor of the luminous ring, 
but should simply be the means of drawing our attention to 
the differences existing between that which appertains to the 
air of heaven (the realms of universal space) and that which 
belongs to the strata of our terrestrial atmosphere. It is not 
possible, as well-attested facts prove, perfectly to explain the 
operations at work in the much-contested upper boundaries of 
our atmosphere. The extraordinary lightness of whole nights 
in the year 1831, during which small print might be read at 
midnight in the latitudes of Italy and the north of Germany, 
is a fact directly at variance with all that we know, accord- 
ing to the most recent and acute researches on the crepuscular 
theory, and of the height of the atmosphere.^ The phenom- 
ena of light depend upon conditions still less understood, and 
their variability at twilight, as well as in the zodiacal light, 
excite our astonishment. 

We have hitherto considered that which belongs to our solar 
system — that world of material forms governed by the Sun — 
which includes the primary and secondary planets, comets of 
short and long periods of revolution, meteoric asteroids, which 
move thronged together in streams, either sporadically or in 
closed rings, and finally a luminous nebulous ring, that re- 
volves round the Sun in the vicinity of the Earth, and for 
which, owing to its position, we may retain the name of zo- 
diacal light. Every where the law of periodicity governs the 
motions of these bodies, however different may be the amount 
of tangential velocity, or the quantity of their agglomerated 
material parts ; the meteoric asteroids which enter our atmos- 
phere from the external regions of universal space are alone 
arrested in the course of their planetary revolution, and re- 
tained within the sphere of a larger planet. In the solar sys- 
tem, whose boundaries determine the attractive force of the 
central body, comets are made to revolve in their elliptical 

* Biot, TraiU d'Asiron. Physique, 3eme ed., 1841, t. i., p. 171, 238. 
and 312. 



TRANSLATORY MOTION OF THE SOLAR SYSTEM. 145 

orbits at a distance 44 times greater than that of Uranus ; 
nay, in those comets whose nucleus appears to us, from its 
inconsiderable mass, like a mere passing cosmical cloud, the 
Sun exercises its attractive force on the outermost parts of the 
emanations radiating from the tail over a space of many mill- 
ions of miles. Central forces, therefore, at once constitute and 
maintain the system. 

Our Sun may be considere'l as at rest when compared to all 
the large and small, dense and almost vaporous cosmical bodies 
that appertain to and revolve around it ; but it actually ro- 
tates round the common center of gravity of the whole sys- 
tem, which occasionally falls within itself, that is to say, re- 
mains within the material circumference of the Sun, what- 
ever changes may be assumed by the positions of the planets. 
A very different phenomenon is that presented by the trans- 
latory motion of the Sun, that is, the progressive motion of 
the center of gravity of the whole solar system in universal 
space. Its velocity is such* that, according to Bessel, the 
relative motion of the Sun, and that of 6 1 Cygni, is not less 
m one day than 3,336,000 geographical miles. This change 
of the entire solar system would remain unknown to us, if the 
admirable exactness of our astronomical instruments of meas- 
urement, and the advancement recently made in the art of 
observinff, did not cause our advance toward remote stars to 
be perceptible, like an approximation to the objects of a dis- 
tant shore in apparent motion. The proper motion of the star 
6 1 Cygni, for instance, is so considerable, that it has amount- 
ed to a whole degree in the course of 700 years. 

The amount or quantity of these alterations in the fixed 
stars (that is to say, the changes in the relative position of 
self-luminous stars toward each other), can be determined 
with a greater degree of certainty than we are able to attach 
to the genetic explanation of the phenomenon. After taking 
into consideration what is due to the precession of the equi- 
noxes, and the nutation of the earth's axis produced by the 
action of the Sun and Moon on the spheroidal figure of our 
globe, and what may be ascribed to the transmission of light, 
that is to say, to its aberration, and to the parallax formed by 
the diametrically opposite position of the Earth in its course 
round the Sun, we still find that there is a residual portion 

* Bessel, in Schura., Jalirh.fur 1839, s. 51; probably four millions 
of miles daily, iu a relative velocity of at the least 3,336,000 miles, or 
more than double the velocity of revolution of the Earth in her orbit 
round the Sun. 
Vol. I.— G 



1 46 COd.MOS. 

of the annual motion of the fixed stars due to the translatiou 
of thy whole solar system in universal space, and to the true 
proper motion of the stars. The difficult problem of numer- 
ically separating these two elements, the true and the appar- 
ent motion, has been effected by the careful study of the di- 
rection of the motion of certain individual stars, and by the 
consideration of the fact that, if all the stars were in a state 
of absolute rest, they would appear perspectively to recede 
from the point in space toward which the Sun was directing 
its course. But the ultimate result of this investigation, con- 
firmed by the calculus of probabilities, is, that our solar sys- 
tem and the stars both change their places in space. Accord- 
ing to the admirable researches of Argelander at Abo, who 
has extended and more perfectly developed the work begun by 
William Herschel and Prevost, the Sun moves in the direc- 
tion of the constellation Hercules, and probably, from the 
combination of the observations made of 537 stars, toward a 
point lying (at the equinox of 1792-5) at 257° 49'-7 R.A., and 
28° 49''7 N.D. It is extremely difficult, in investigations of 
this nature, to separate the absolute from the relative motion, 
and to determine what is alone owing to the solar system.* 

If we consider the proper, and not the perspective motions 
of the stars, we shall find many that appear to be distributed 
in groups, having an opposite direction ; and facts hitherto 
observed do not, at any rate, render it a necessary assumption 
that all parts of our starry stratum, or the whole of the stellar 
islands filling space, should move round one large unknown 
luminous or non-luminous central body. The tendency of the 
human mind to investigate ultimate and highest causes cer- 
tainly inclines the intellectual activity, no less than the imag- 
ination of mankind, to adopt such an hypothesis. Even the 
Stagirite proclaimed that " every thing which is moved must 
be referable to a motor, and that there would be no end to 



* Regarding the motion of the solar system, according to Bradley, 
Tobias Mayer, Lambert, Lalaude, and William Herschel, see Arago,iu 
the Anmiaire, 1842, p. 388-399; Argelander, in Schum., Asfron. Nachr., 
No. 363, 364, 398, and in the treatise Voti der eigcnen Bewegnng des 
Soymensy stems (On the proper Motion of the Solar System), 1837, s. 43, 
respecting Perseus as the central body of the whole stellar stratum, 
likewise Otho Struve, in the Bull, de V Acad, de St. Petersh., 1842, t. x., 
No. 9, p. 137-139. The last-named astronomer has found, by a more 
recent combination, 261^ 23' R.A.4-37° 36' Decl. for the direction of 
the Sun's motion; and, taking the mean of his own results with that of 
Argelander, we have, by a combination of 797 stars, the formula 259" 
3' R.A. 4- 34° 36' Decl. 



TRANSLATORY MOTION. 14T 

the concatenation of causes if there were not one primordiai 
immovable motor."* 

The manifold translatory changes of the stars, not those 
produced by the parallaxes at which they are seen from the 
changing position of the spectator, but the true changes con- 
stantly going on in the regions of space, afford us incontro- 
vertible evidence of the dominion of the laws of attraction in 
the remotest regions of space, beyond the limits of our solar 
system. The existence of these laws is revealed to us by 
many phenomena, as, for instance, by the motion of double 
stars, and by the amount of retarded or accelerated motion in 
different parts of their elliptic orbits. Human inquiry need 
no longer pursue this subject in the domain of vague conjec- 
ture, or amid the undefined analogies of the ideal world ; for 
even here the progress made in the method of astronomical 
observations and calculations has enabled astronomy to take 
up its position on a firm basis. It is not only the discovery 
of the astounding numbers of double and multiple stars re- 
volving round a center of gravity lying ivitliout their system 
(2800 such systems having been discovered up to 1837), but 
rather the extension of our knowledge regarding the funda- 
mental forces of the whole material world, and the proofs we 
have obtained of the universal empire of the laws of attrac- 
tion, that must be ranked among the most brilliant discoveries 
of the age. The periods of revolution of colored stars present 
the greatest differences ; thus, in some instances, the period 
extends to 43 years, as in 7\ of Corona, and in others to sev- 
eral thousands, as in 66 of Cetus, 38 of Gemini, and 100 of 
Pisces. Since Herschel's measurements in 1782, the satellite 
of the nearest star in the triple system of ^ of Cancer has com- 
pleted more than one entire revolution. By a skillful com- 
bination of the altered distances and angles of position,! the 
elements of these orbits may be found, conclusions drawn re- 
garding the absolute distance of the double stars from the 
Earth, and comparisons made between their mass and that 
of the Sun, Whether, however, here and in our solar sys- 
tem, quantity of matter is the only standard of the amount 
of attractive force, or whether specific forces of attraction pro- 
portionate to the mass may not at the same time come into 
operation, as Bessel was the first to conjecture, are questions 

* Aristot., de Caelo, iii., 2, p. 301, Bekker ; Phys., viii., 5, p. 256. 

t Savary, in the Connaissance des Terns, 1830, p. 56 and 163. Encke, 
Berl. Jahrb.. 1832, s. 253, &c. Arago, in the Annuaire, 1834, p. 260 
295. John Herschel, in the Memoirs of the Astronom. Soc, vol. v., p. 17 1 



148 COSMOS. 

whose practical solution must be left to future ages.* When 
we compare our Sun with the other fixed stars, that is, with oth 
er self-luminous Suns in the lenticular starry stratum of which 
our system forms a part, we find, at least in the case of some, 
that channels are opened to us, which may lead, at all events, 
to an approximate and limited knowledge of their relative 
distances, volumes, and masses, and of the velocities of their 
translatory motion. If we assume the distance of Uranus 
from the Sun to be nineteen times that of the Earth, that is 
to say, nineteen times as great as that of the Sun from the 
Earth, the central body of our planetary system will be 11, 900 
times the distance of Uranus from the star a in the constella- 
tion Centaur, almost 31,300 from 61 Cygni, and 41,600 from 
Vega in the constellation Lyra. The comparison of the vol- 
ume of the Sun with that of the fixed stars of the first mag- 
nitude is dependent upon the apparent diameter of the latter 
bodies — an extremely uncertain optical element. If even we 
assume, with Herschel, that the apparent diameter of Arctu- 
rus is only a tenth part of a second, it still follows that the 
true diameter of this star is eleven times greater than that of 
the Sun.f The distance of the star 61 Cygni, made known 
by Bessel, has led approximately to a knowledge of the quan- 
tity of matter contained in this body as a double star. Not- 
withstanding that, since Bradley's observations, the portion 
of the apparent orbit traversed by this star is not sufficiently 
great to admit of our arriving with perfect exactness at the 
true orbit and the major axis of this star, it has been conjec- 
tured with much probability by the great Konigsberg astron- 
omer,t " that the mass of this double star can not be very con- 
siderably larger or smaller than half of the mass of the Sun." 
This result is from actual measurement. The analogies de- 
duced from the relatively larger mass of those planets in our 
solar system that are attended by satellites, and from the fact 
that Struve has discovered six times more double stars among 

* Bessel, Untersuchung. des Theils der planetaHschen Storungen, 
welcke aus der Betcegumg der Sonne entsieken (An Investigation of the 
portion of the Planetary Disturbances depending on the Motion of the 
Sun) in Abh. der Berl. Akad. der Wissensch., 1824 (Mathem. Classe), 
8. 2-6. The question has been raised by John Tobias Mayer, in Com- 
ment. Soc. Reg. Gotting., 1804-1808, vol. xvi., p. 31-68. 

t Fkilos. Trans, for 1803, p. 225. Arago, in the Annuaire, 1842, p. 
375. In order to obtain a clearer idea of the distances ascribed in a 
rather earlier part of the text to the fixed stars, let us assume that the 
Earth is a distance of one foot from the Sun; Uranus is then 19 feet, 
and Vega Lyrae is 158 geographical miles from it. 

X Bessel, in Schum., Jahrb., 1839, s. 53. 



TRANSLATORY MOTION. l49 

the brighter than among the telescopic fixed stars, have led 
other astronomers to conjecture that the average mass of the 
larger number of the binary stars exceeds the mass of the 
Sun.* We are, however, far from having arrived at general 
results regarding this subject. Our Sun, according to Arge- 
lander, belongs, with reference to proper motion in space, to 
the class of rapidly-moving fixed stars. 

The aspect of the starry heavens, the relative position of 
stars and nebulse, the distribution of their luminous masses, 
the picturesque beauty, if I may so express myself, of the 
whole firmament, depend in the course of ages conjointly upon 
the proper motion of the stars and nebulse, the translation of 
our solar system in space, the appearance of new stars, and 
the disappearance or sudden diminution in the intensity of the 
light of others, and, lastly and specially, on the changes which 
the Earth's axis experiences from the attraction of the Sun 
and Moon. The beautiful stars in the constellation of the 
Centaur and the Southern Cross will at some future time be 
visible in our northern latitudes, while other stars, as Sirius 
and the stars in the Belt of Orion, will in their turn disappear 
below the horizon. The places of the North Pole will suc- 
cessively be indicated by the stars (3 and a Cephei, and 6 Cygni, 
until after a period of 12,000 years, Vega in Lyra will shine 
forth as the brightest of all possible pole stars. These data 
give us some idea of the extent of the motions which, divided 
into infinitely small portions of- time, proceed without inter- 
mission in the great chronometer of the universe. If for a 
moment we could yield to the power of fancy, and imagine 
the acuteness of our visual organs to be made equal with the 
extremest bounds of telescopic vision, and bring together that 
which is now divided by long periods of time, the apparent 
rest that reigns in space would suddenly disappear. We 
should see the countless host of fixed stars movinor in throngfed 
groups in difierent directions ; nebulse w^andering through 
space, and becoming condensed and dissolved like cosmical 
clouds ; the vail of the Milky Way separated and broken up 
in many parts, and motion ruling supreme in every portion of 
the vault of heaven, even as on the Earth's surface, where we 
see it unfolded in the germ, the leaf, and the blossom, the or 
ganisms of the vegetable world. The celebrated Spanish bot 
anist Cavanilles was the first who entertained the idea of 
" seeing grass grow," and he directed the horizontal microme- 
ter threads of a powerfully magnifying glass at one time to 
* Madler, Astron., s. 476; also in Schum.. Jahrb., 1839, s. 9.5. 



150 COSMOS. 

the apex of the shoot of a bambusa, and at another on the 
rapidly-growing stem of an American aloe [Agave Americmia), 
precisely as the astronomer places his cross of net- work against 
a culminating star. In the collective life of physical nature, 
in the organic as in the sidereal world, all things that have 
been, that are, and will be, are alike dependent on motion. 

The breaking up of the Milky Way, of which I have just 
spoken, requires special notice. William Herschel, our safe 
and admirable guide to this portion of the regions of space, 
has discovered by his star-guagings that the telescopic breadth 
of the Miiky Way extends from six to seven degrees beyond 
what is indicated by our astronomical maps and by the extent 
of the sidereal radiance visible to the naked eye.* The two 
brilliant nodes in which the branches of the zone unite, in the 
region of Cepheus and Cassiopeia, and in the vicinity of Scor- 
pio and Sagittarius, appear to exercise a powerful attraction 
on the contiguous stars ; in the most brilliant part, however, 
between /3 and y Cj^gni, one half of the 330,000 stars that 
have been discovered in a breadth of 5^ are directed toward 
one side, and the remainder to the other. It is in this part 
that Herschel supposes the layer to be broken up.f The num- 
ber of telescopic stars in the Milky Way uninterrupted by any 
nebulEe is estimated at 18 millions. In order, I will not say, 
to realize the greatness of this number, but, at any rate, to 
compare it with something analogous, I will call attention to 
the fact that there are not in the whole heavens more than 
about 8000 stars, between the first and the sixth magnitudes, 
visible to the naked eye. The barren astonishment excited 
by numbers and dimensions in space, when not considered 
with reference to applications engaging the mental and per- 
ceptive powers of man, is awakened in both extremes of the 
universe, in the celestial bodies as in the minutest animal- 
cules. $ A cubic inch of the polishing slate of Bilin contains, 
according to Ehrenberg, 40,000 millions of the silicious shells 
of GalionellsB. 

The stellar Milky Way, in the region of which, according to 
Argelander's admirable observations, the brightest stars of the 
firmament appear to be congregated, is almost at right angles 

* Sir William Herschel, in the Pkilos. Transact, for 1817, Part ii. 
p. 328. t Arago, in the Anmiaire, 1842, p. 459. 

X Sir JoliQ Herschel, in a letter from Feldhuysen, dated Jan. 13th, 
1836. Nicholl, Architecture of the Heavens, 1838, p. 22. (See, also, 
some separate notices by Sir William Herschel on the starless space 
which separates us by a great distance from the Milky Way, in the 
Philos. Transact, for 1817, Part ii., p. 328.) 



THK MII.lvV WAV. 151 

with another Milky Way, composed of nebulai. The Ibrmer 
constitutes, according to Sir J ohn Herschel's views, an annu- 
lus, that is to say, an independent zone, somewhat remote from 
our lenticular-shaped starry stratum, and similar to Saturn's 
ring. Our planetary system lies in an eccentric direction, 
nearer to the region of the Cross than to the diametrically op- 
posite point, Cassiopeia.* An imperfectly seen nebulous spot, 
discovered by Messier in 1774, appeared to present a remark- 
able similarity to the form of our starry stratum and the divided 
ring of our Milky Way.t The Milky V/ay composed of neb- 
ula; does not belong to our starry stratum, but surrounds it at 
a great distance without being physically connected with it, 
passing ahiiost in the form of a large cross through the dense 
nebulae of Virgo, especially in the northern wing, through 
Comae Berenicis, Ursa Major, Andromeda's girdle, and Pisces 
Boreales. It probably intersects the stellar Milky Way in 
Cassiopeia, and connects its dreary poles (rendered starless from 
the attractive forces by which stellar bodies are made to ag- 
glomerate into groups) in the least dense portion of the starry 
stratum. 

We see from these considerations that our starry cluster, 
which bears traces in its projecting branches of having been 
subject in the course of time to various metamorphoses, and 
evinces a tendency to dissolve and separate, owing to second- 
ary centers of attraction — is surrounded by two rings, one of 
which, the nebulous zone, is very remote, while the other is 
nearer, and composed of stars alone. The latter, which wo 
generally term the Milky Way, is composed of nebulous stars, 
avera^ino- from the tenth to the eleventh degree of magni- 
tude,| but appearing, when considered individually, of very 
difierent magnitudes, while isolated starry clusters (starry 
swarms) almost always exhibit throughout a character of 
great uniformity in magnitude and brilliancy. 

In whatever part the vault of heaven has been pierced by 
powerful and far-penetrating telescopic instruments, stars or 
luminous nebulss are every where discoverable, the former, in 

* Sir John Herschel, Astronom.., § 624; likewise in his Obsei'vations 
■)n Nebulceand Clusters of Stars {Phil. Transact. ^ 1833, Part ii.,p. 479, 
fig. 25) : " We have here a brother system, bearing a real physical re 
jemblauce and strong analogy of structure to our own." 

t Sir William Herschel, in the Phil. Trans, for 1785, Part i., p. 257. 
Sir .John Herschel, Astron., $ 61G. (" The nebulous region of the heav- 
ens forms a nebulous Milky Way, composed of distinct uebulse, as the 
other of stars." The same observation was made in a letter he addressed 
to mfi in March. 1829.) t Sir John Herschel, Astron., $ 585. 



152 COSMOS. 

Bome cases, not exceeding the twentieth or twenty-fourth de 
gree of telescopic magnitude. A portion of the nebulous vapoi 
would probably be found resolvable into stars by more power 
ful optical instruments. As the retina retains a less vivid im- 
pression of separate than of infinitely near luminous points, 
less strongly marked photometric relations are excited in the 
latter case, as Arago has recently shown.* The definite or 
amorphous cosmical vapor so universally diffused, and which 
generates heat through condensation, probably modifies the 
transparency of the universal atmosphere, and diminishes that 
uniform intensity of light which, according to Halley and Gi- 
bers, should arise, if every point throughout the depths of space 
were filled by an infinite series of stars. f The assumption of 
such a distribution in space is, however, at variance with ob- 
servation, which shows us large starless regions of space, 02:)en- 
ings in the heavens, as William Herschel terms them — one, 
four degrees in width, in Scorpio, and another in Serpentari- 
us. In the vicinity of both, near their margin, we find un- 
resolvable nebulae, of which that on the western edge of the 
opening in Scorpio is one of the most richly thronged of the 
clusters of small stars by which the firmament is adorned. 
Herschel ascribes these openings or starless regions to the at- 
tractive and agglomerative forces of the marginal groups. $ 
" They are parts of our starry stratum," says he, with his 
usual graceful animation of style, " that have experienced 
great devastation from time." If we picture to ourselves the 
telescopic stars lying behind one another as a starry canopy 
spread, over the vault of heaven, these starless regions in Scor- 
pio and Serpentarius may, I think, be regarded as tubes 
through which we may look into the remotest depths of space. 
Other stars may certainly lie in those parts where the strata 
forming the canopy are interrupted, but these are unattainable 
by our instruments. The aspect of fiery meteors had led the 
ancients likewise to the idea of clefts or openings [cJiasmata) 
in the vault of heaven. These openings were, however, only 
regarded as transient, while the reason of their being luminous 
and fiery, instead of obscure, was supposed to be owing to the 

* Arago, iu the Annuaire, 1842, p. 282-285, 409-411, and 439-442. 

t Olbers, on the transparency of celestial space, in Bode's Jalirh., 
1826, s. 110-121. 

X " An opening in the heavens," William Hersche],in the Phil. Trans. 
for 1785, vol. Ixxv., Part i., p. 256. Le Fran9ais Lalande, in the Con- 
naiss. des Terns pour V An. VIII., p. 383. Arago, in the Annuaire, 
1842, p. 425. 



STARLESS OPENINGS. 153 

translucent illuminated ether which lay beyond them.* Der- 
ham, and even Huygens, did not appear disinclined to explain 
in a similar manner the mild radiance of the nebuleB.f 

When we compare the stars of the first magnitude, which, 
on an average, are certainly the nearest to us, with the non- 
nebulous telescopic stars, and further, when we compare the 
nebulous stars with unresolvable nebulae, for instance, with 
the nebula in Andromeda, or even with the so-called planetary 
nebulous vapor, a fact is made manifest to us by the consider- 
ation of the varying distances and the boundlessness of space, 
which shows the world of phenomena, and that which con- 
stitutes its causal reality, to be dependent upon the ])ropaga- 
tion of light. The velocity of this propagation is, according 
to Struve's most recent investigations, 166,072 geographical 
miles in a second, consequently almost a million of times 
greater than the velocity of sound. According to the meas- 
urements of Maclear, Bessel, and Struve, of the parallaxes 
and distances of three fixed stars of very unequal magnitudes 
{a Centauri, 16 Cygni, and a Lyrse), a ray of light requires 
respectively 3, 9^^. and 12 years to reach us from these three 
bodies. In the short but memorable period between 1572 
and 1604, from the time of Cornelius Gemma and Tycho 
Brahe to that of Kepler, three new stars suddenly appeared 
in Cassiopeia and Cygnus, and in the foot of Serpentarius. 
A similar phenomenon exhibited itself at intervals in 1670, in 
the constellation Vulpis. In recent times, even since 1837, 
Sir John Herschel has observed, at the Cape of Good Hope, 
the brilliant star r\ in Argo increase in splendor from the 
second to the first magnitude 4 These events in the universe 
belong, however, with reference to their historical reality, to 
other periods of time than those in which the phenomena of 
light are first revealed to the inhabitants of the Earth : they 
reach us like the voices of the past. It has been truly said, 
that with our large and powerful telescopic instruments we 
penetrate alike through the boundaries of time and space : we 
measure the former through the latter, for in the course of an 

* Aristot., Meteor., ii., 5, 1. Seneca, Natur. Qucest., i., 14, 2. " Cce- 
lum discessisse," in Gic, de Divin., i., 43. 

t Arago, in the Annuaire, 1842, p. 429. 

X In December, 1837, Sir John Herschel saw the star ;; Argo, which 
till that time appeared as of the second magnitude, and liable to no 
change, rapidly increase till it became of the first magnitude. In Jan- 
uary, 1838, the intensity of its light was equal to that of a Centauri. 
According to our latest information, Maclear, in March, 1843, found it 
as bright as Canopus; and even a Crucis looked faint by rj Argo. 

G2 



154 COSMOS. 

hour a ray of light traverses over a space of 592 miHions of 
miles. While, according to the theogony of Hesiod, the di- 
mensions of the universe were supposed to be expressed by the 
time occupied by bodies in falling to the ground (" the brazen 
anvil was not more than nine days and nine nights in falling 
from heaven to earth"), the elder Herschel was of opinion* 
that light required almost two millions of years to pass to the 
Earth from the remotest luminous vapor reached by his forty- 
foot reflector. Much, therefore, has vanished long before it 
is rendered visible to us — much that we see was once differ- 
ently arranged from what it now appears. The aspect of the 
starry heavens presents us with the spectacle of that which 
is only apparently simultaneous, and however much we may 
endeavor, by the aid of optical instruments, to bring the mild- 
ly-radiant vapor of nebulous masses or the faintly-glimmering 
starry clusters nearer, and diminish the thousands of years 
interposed between us and them, that serve as a criterion of 
their distance, it still remains more than probable, from the 
knowledge we possess of the velocity of the transmission of 
luminous rays, that the light of remote heavenly bodies pre- 
sents us with the most ancient perceptible evidence of the ex- 
istence of matter. It is thus that the reflective mind of man 
is led from simple premises to rise to those exalted heights of 
nature, where, in the light-illumined realms of space, " myriads 
of worlds are bursting into life like the grass of the night. "f 
From the regions of celestial forms, the domain of Uranus, 
we will now descend to the more contracted sphere of terres- 
trial forces — to the interior of the Earth itself A mysterious 
chain links together both classes of phenomena. According 
to the ancient signification of the Titanic myth,$ the powers 
of organic life, that is to say, the great order of nature, depend 
upon the combined action of heaven and earth. If we sup- 
pose that the Earth, like all the other planets, primordially 
belonged, according to its origin, to the central body, the Sun, 
and to the solar atmosphere that has been separated into neb- 

* " Hence it follows that the rays of hght of the remotest nebulae 
must have been almost two millions of years on their way, and that 
consequently, so many years ago, this object must already have had 
an existence in the sidereal heaven, in order to send out those rays by 
which we now perceive it." William Herschel, in the Phil. Trans. 
for 1802, p. 498. John Herschel, Astron., $ 590. Arago, in the An- 
nuaire, 1842. p. 334, 359, and 382-385. 

t From my brother's beautiful sonnet " Freiheitund Gesetz." (Wil- 
helm von Humboldt, Gesammelte Werhe, bd. iv., s. 358, No. 25.) 

X Otfried MOUer, Prolegomena, s. 373. 



TERRESTRIAT. PHENOMENA. 155 

ulous rings, the same connection with this contiguous Sun, as 
well as with all the remote suns that shine in the firmament, 
is still revealed through the phenomena of light and radiating 
heat. The difference in the degree of these actions must not 
lead the physicist, in his delineation of nature, to forget the 
connection and the common empire of similar forces in the 
universe. A small fraction of telluric heat is derived from 
the- regions of universal space in which our planetary system 
is moving, whose temperature (which, according to Fourier, 
is almost equal to our mean icy polar heat) is the result of the 
combined radiation of all the stars. The causes that more pow- 
erfully excite the light of the Sun in the atmosphere and in the 
upper strata of our air, that give rise to heat-engendering elec- 
tric and magnetic currents, and awaken and genially vivify 
the vital spark in organic structures on the earth's surface, 
must be reserved for the subject of our future consideration. 

As we purpose for the present to confine ourselves exclusive- 
ly within the telluric sphere of nature, it will be expedient to 
cast a preliminary glance over the relations in space of solids 
and fluids, the form of the Earth, its mean density, and the 
partial distribution of this density in the interior of our planet, 
its temperature and its electro-magnetic tension. From the 
consideration of these relations in space, and of the forces in- 
herent in matter, we shall pass to the reaction of the interior 
on the exterior of our globe ; and to the special consideration 
of a universally distributed natural power — subterranean heat ; 
to the phenomena of earthquakes, exliibited in unequally ex- 
panded circles of commotion, which are not referable to the 
action of dynamic laws alone ; to the springing forth of hot 
wells ; and, lastly, to the more powerful actions of volcanic 
processes. The crust of the Earth, which may scarcely have 
been perceptibly elevated by the sudden and repeated, or al- 
most uninterrupted shocks by M^hich it has been moved from 
below, undergoes, nevertheless, great changes in the course of 
centuries in the relations of the elevation of solid portions, 
wdien compared with the surface of the liquid parts, and even 
in the form of the bottom of the sea. In this manner si- 
multaneous temporary or permanent fissures are opened, by 
which the interior of the Earth is brought in contact with 
the external atmosphere. Molten masses, rising from an un- 
known depth, flow in narrow streams along the declivity of" 
mountains, rushing impetuously onward, or moving slowly 
and gently, until the fiery source is quenched in the niidst of 
exlialations, and the lava becomes incrusted, as it were, by 



156 COSMOS. 

the solidification of its outer surface. New masses of rocks 
are thus formed before our eyes, while the older ones are in 
their turn converted into other forms by the greater or lesser 
agency of Plutonic forces. Even where no disruption takes 
place the crystalline molecules are displaced, combining to 
Ibrm bodies of denser texture. The water presents structures 
of a totally different nature, as, for instance, concretions of 
animal and vegetable remains, of earthy, calcareous, or alumin- 
ous precipitates, agglomerations of finely-pulverized mineral 
bodies, covered with layers of the silicious shields of infusoria, 
and with transpwted soils containing the bones of fossil ani- 
mal forms of a more ancient world. The study of the strata 
which are so differently formed and arranged before our eyes, 
and of all that has been so variously dislocated, contorted, and 
upheaved, by mutual compression and volcanic force, leads 
the reflective observer, by simple analogies, to draw a com- 
parison between the present and an age that has long passed. 
It is by a combination of actual phenomena, by an ideal en- 
largement of relations in space, and of the amount of active 
forces, that we are able to advance into the long sought and 
indefinitely anticipated domain of geognosy, which has only 
within the last half century been based on the solid founda- 
tion of scientific deduction. 

It has been acutely remarked, " that, notwithstanding our 
continual employment of large telescopes, we are less ac- 
quainted with the exterior than with the interior of other 
planets, excepting, perhaps, our own satellite." They have 
been weighed, and their volume measured ; and their mass 
and density are becoming known with constantly-increasing 
exactness ; thanks to the progress made in astronomical ob- 
servation and calculation. Their physical character is, how- 
ever, hidden in obscurity, for it is only in our own globe that 
we can be brought in immediate contact with all the ele- 
ments of organic and inorganic creation. The diversity of 
the most heterogeneous substances, their admixtures and met- 
amorphoses, and the ever-changing play of the forces called 
into action, afford to the human mind both nourishment and 
enjoyment, and open an immeasurable field of observation, 
from which the intellectual activity of man derives a great 
portion of its grandeur and power. The world of perceptive 
phenomena is reflected in the depths of the ideal world, and 
the richness of nature and the mass of all that admits of clas- 
sification gradually become the objects of inductive reasoning. 

I would here allude to the advantage, of which I have al- 



TERRESTRIAL PHENOMENA. 157 

ready spoken, possessed by that portion of physical science 
whose origin is famihar to us, and is connected with our earth- 
ly existence. The physical description of celestial bodies, from 
the remotely-glimmering nebulae with their suns, to the central 
body of our own system, is limited, as we have seen, to gen- 
eral conceptions of the volume and quantity of matter. No 
manifestation of vital activity is there presented to our senses. 
It is only from analogies, frequently from purely ideal com- 
binations, that we hazard conjectures on the specific elements 
of matter, or on their various modifications in the different 
planetary bodies. But the physical knowledge of the het- 
erogeneous nature of matter, its chemical differences, the reg- 
ular farms in which its molecules combine together, whether 
in crystals or granules ; its relations to the deflected or de- 
composed waves of Hght by which it is penetrated ; to radi- 
ating, transmitted, or polarized heat ; and to the brilHant or 
invisible, but not, on that account, less active phenomena of 
electro-magnetism — all this inexhaustible treasure, by which 
the enjoyment of the contemplation of nature is so much 
heightened, is dependent on the surface of the planet which 
we inhabit, and more on its solid than on its liquid parts. I 
have already remarked how greatly the study of natural ob- 
jects and forces, and the infinite diversity of the sources they 
open for our consideration, strengthen the mental activity, and 
call into action every manifestation of intellectual progress. 
These relations require, however, as little comment as that 
concatenation of causes by which particular nations are per- 
mitted to enjoy a superiority over others in the exercise of a 
material power derived from their command of a portion of 
these elementary forces of nature. 

If, on the one hand, it were necessary to indicate the dif- 
ference existing between the nature of our knowledge of the 
Earth and of that of the celestial regions and their contents, 
I am no less desirous, on the other hand, to draw attention 
to the limited boundaries of that portion of space from which 
we derive all our knowledge of the heterogeneous character 
of matter. This has been somewhat inappropriately termed 
the Earth's crust ; it includes the strata most contiguous to 
the upper surface of our planet, and which have been laid 
open before us by deep fissure-like valleys, or by the labors of 
man, in the bores and shafts formed by miners. These labors* 

* In speaking of the greatest depths within the Earth reached by hu 
man labor, we must recollect that there is a ditference between the (tb- 
solute depth (that is to say, the depth below the Earth's surface ut tii;i. 



156 COSxMOS. 

do not extend beyond a vertical depth of somewhat more than 
2000 feet (about one third of a geographical mile) below the 

point) and the relative depth (or that beneath the level of the sea). The 
greatest relative depth that man has hitherto reached is probably the 
bore at the new salt- works at Minden, in Prussia: in June, 1844, it 
was exactly 1993 feet, the absolute depth being 2231 feet. The tern 
perature of the water at the bottom was 91° F., which, assuming the 
mean temperature o4' the air at 49°-3, gives an augmentation of tem- 
perature of 1° for every 54 feet. The absolute depth of the Artesian 
well of Grenelle, near Paris, is only 1795 feet. According to the ac- 
count of the missionary Imbert, the fire-springs, " Ho-tsing," of the Chi- 
nese, which are sunk to obtain [carbureted] hydrogen gas for salt-boil- 
ing, far exceed our Artesian springs in depth. In the Chinese province 
of Szii-tschuan these fire-springs are very commonly of the depth of 
more than 2000 feet; indeed, at Tseu-lieu-tsing (the place of continual 
flowj there is a Ho-tsing which, in the year 1812, was found to be 3197 
feet deep. (Humboldt, Asie Centrale, t. ii., p. 521 and 525. Annales 
de V Association de la Propagation de la Foi, 1829, No. 16, p. 369.) 

The relative depth reached at Mount Massi, in Tuscany, south of 
Vol terra, amounts, according to Matteuci, to only 1253 feet. The bor- 
ing at the new salt-works near Minden is probably of about the same 
relative depth as the coal-mine at Apendale, near Newcastle-under- 
Lyme, in Staifordshire, where men work 725 yards below the surface 
of the earth. (Thomas Smith, Miner's Guide, 1836, p. 160.) Unfortu- 
nately, I do not know the exact height of its mouth above the level 
of the sea. The relative depth of the Monk-wearmouth mine, near 
Newcastle, is only 1496 feet. (Phillips, in the Philas. Mag., vol. v., 
1834, p. 446.) That of the Liege coal-mine, V Espirance, at Seraing, 
is 1355 feet, according to M. von Dechen, the director ; and the old 
mine of Marihaye, near Val-St.-Lambert, in the valley of the Maes, 
is, according to M. Gernaert, Ingenieur des Mines, 1233 feet in depth. 
The works of greatest absolute depth that have ever been formed 
are for the most part situated in such elevated plains or valleys that 
they either do not descend so low as the level of the sea, or at most 
reach very little below it. Thus the Eselschacht, at Kuttenberg, in Bo- 
hemia, a mine which can not now be worked, had the enormous abso- 
lute depth of 3778 feet. (Fr. A. Schmidt, Berggesetze der oster Mon., 
abth. i., bd. i., s. xxxii.) Also, at St. Daniel and at Geish, on the Rorer- 
biihel, in the Landgericht (or provincial district) of Kitzbiihl, there 
were, in the sixteenth century, excavations of 3107 feet. The plans 
of the works of the Rorerbtihel are still preserved. (See Joseph von 
Sperges. Tyroler Bergwerksgeschichte, s. 121. Compare, also, Hum- 
boldt, Gutachten uher Herantreibung des Meissner Stollens in die Frei- 
berger Erzrevier, printed in Herder, uber den jetz bcgonnenen Erbstol- 
len, 1838, s. cxxiv.) We may presume that the knowledge of the ex- 
traordinary depth of the Rorerbiihel reached England at an early period, 
for I find it remarked in Gilbert, de Magnete, that men have penetrated 
2400 or even 3000 feet into the crust of the Earth. (" Exigua videtur 
terrse portio, quae unquam hominibus spectanda emerget aut eruitur: 
cum profundius in ejus viscera, ultra ♦florescentis extremitatis coirupte- 
lam. aut propter aquas in magnis fodin tanquam per venas scaturientes 
aut propter aeris salubrioris ad vitam o erariorum sustinendani neces- 
sarii defectum, aut propter ingentes sumf tus ad tautos labures exant- 
landos, multasque difficultates, ad profundi n-es terrte partes peuetrare 



TERRESTRIAL PHENOMENA. 150 

level of the sea, and consequently only about g^VTr^^^ of the 
Earth's radius. The crystalUne masses that have been erupt- 
ed from active volcanoes, and are generally similar to the 
rocks on the upper surface, have come from depths which, 
although not accurately determined, must certainly be sixty 
times greater than those to which human labor has been ena- 
bled to penetrate. We are able to give m numbers the depth 
of the shaft where the strata of coal, after penetrating a cer- 
tain way, rise again at a distance that admits of being accu- 
rately defined by measurements. These dips show that the 
carboniferous strata, together with the fossil organic remains 
which they contain, must lie, as, for instance, in Belgium, 
more than five or six thousand feet* below the present level 

non possumus; adeo ut quadi-ingeutas aut [quod rarissime] quiugeiitas 
orgyas iii quibusdam inetiillis desceiidisse, stupeudus omnibus videatur 
conatus." — Gulielmi Gilbert!, Colcestreusis, de Magnate Physiologia 
nova. Loud., 1600, p. 40.) 

Tiie absolute depth of the mines iu the Saxon Erzgebirge, near Frei 
bure, ai'e : in the Tharmhofer mines, 1944 feet; in the Honeubirker 
mines, 1827 feet ; the i-elative depths are only 677 and 277 feet, if, in 
order to calculate the elevation of the mine's mouth above the level of 
the sea, we regard the elevation of Freiburg as determined by Reich^ 
recent observations to be 1269 feet. The absolute depth of the cele- 
brated mine of Joachimsthal, in Bohemia (Verkreuzung des Jung Hauer 
Zechen-und Andreasganges), is full 2120 feet ; so that, as Von Dechen's 
measurements show that its surface is about 2388 feet above the level 
of the sea, it follows that the excavations have not as yet reached that 
point. In the Harz, the Samson mine at Andreasberg has an absolute 
depth of 2197 feet. In what was formerly Spanish America, I know 
of no mine deeper than the Valenciana, near Guanaxuato (Mexico), 
where I found the absolute depth of the Planes de San Bernardo to be 
1686 feet ; but these planes are 5960 feet above the level of the sea. 
If we compare the depth of the old Kuttenberger mine (a depth great- 
er than the height of our Brockeu, and only 200 feet less than that of 
Vesuvius) with the loftiest structures that the hands of man have erect- 
ed (with the Pyramid of Cheops and with the Cathedral of Strasburg), 
we find that they stand in the ratio of eight to one. In this note I have 
collected all the certain information I could find regarding the great- 
est absolute and relative depths of mines and borings. In descending 
eastward ft-om Jerusalem toward the Dead Sea, a view presents itself 
to the eye, which, according to our pi'esent hypsometrical knowledge 
of the surface of our planet, is unrivaled in any country ; as we ap- 
proach the open ravine through which the Jordan takes its course, we 
tread, with the open sky above us, on rocks which, according to the ba- 
rometric measurements of Berton and Russegger, are 1385 feet below the 
level of the Mediterranean. (Humboldt, Asie Cenirale, th. ii., p. 323.) 

* Basin-shaped curved strata, which dip and reappear at measurable 
distances, although their deepest portions are beyond the reach of the 
miner, afford sensible evidence of the nature of the earth's ciixst at great 
depths below its surface. Testimony of this kind possesses, consequent- 
ly, a great geognostic interest. I am indebted to that excellent geog- 



160 COSMOS. 

Df the sea, and that the calcareous and the curved strata of 
the Devonian basin penetrate twice that depth. If w^e com- 
pare these subterranean basins with the summits ot" mountains 
that have hitherto been considered as the most elevated por- 
tions of the raised crust of the Earth, we obtain a distance of 
37,000 feet (about seven miles), that is, about the j-jjth of 
the Earth's radius. These, therefore, would be the limits of 
vertical depth and of the superposition of mineral strata to 
which geognostical inquiry could penetrate, even if the gener- 
al elevation of the upper surface of the earth were equal to 
the height of the Dhawalagiri in the Himalaya, or of the 
Sorata in Bolivia. All that lies at a greater depth below the 
level of the sea than the shafts or the basins of which I have 
spoken, the limits to which man's labors have penetrated, or 
than the depths to which the sea has in some few instances 
been sounded (Sir James Ross was unable to find bottom with 
27,600 feet of line), is as much unknown to us as the interior 
of the other planets of our solar system. We only know the 
mass of the whole Earth and its mean density by comparing 
it with the open strata, which alone are accessible to us. In 
the interior of the Earth, where all knowledge of its chemical 
and mineralogical character fails, we are again limited to as 
pure conjecture, as in the remotest bodies that revolve round 
the Sun. We can determine nothing with certainty regard- 
ing the depth at which the geological strata must be supposed 
to be in state of softening or of liquid fusion, of the cavities 
occupied by elastic vapor, of the^ condition of fluids when 
heated under an enormous pressure, or of the law of the in- 

nosist, Von Dechen, for the following observations. "■ The depth of 
the coal basin of Liege, at Mont St. Gilles, which I, in conjunction with 
our friend Von Oeynhausen, have ascertained to be 3890 feet below 
the surface, extends 3464 feet below the surface of the sea, for the ab- 
solute height of Mont St. Gilles certainly does not much exceed 400 
feet ; the coal basin of Mons is fully 1865 feet deeper. But all these 
depths are trifling compared with those w^hich are presented by the 
coal strata of Saar-Revier (SaarbiTJcken). I have found, after repeated 
examinations, that the lowest coal stratum which is known in the neigh- 
borhood of Duttweiler, near Bettingen, northeast of Saarlouis, must de- 
scend to depths of 20,682 and 22,015 feet (or 3-6 geographical miles) 
below the level of the sea." This result exceeds, by more than 8000 
feet, the assumption made in the text regarding the basin of the De- 
vonian strata. This coal-field is therefore sunk as far below the sur- 
face of the sea as Chimborazo is elevated above it — at a depth at which 
the Earth's temperature must be as high as 435° F. Hence, from tlie 
highest pinnacles of the Himalaya to the lowest basins containing the 
vegetation of an earlier world, there is a vertical distance of about 
48,000 feet, or of the 435th part of the Earth's radiu.s. 



GEOGRAPHICAL DISTRIBUTION. 161 

crease of density from the upper surface to tfcfi center of the 
Earth. 

The consideration of the increase of heat with the increase 
of depth toward the interior of our planet, and of the reaction 
of the interior on the external crust, leads us to the long series 
of volcanic phenomena. These elastic forces are manifested 
in earthquakes, eruptions of gas, hot wells, mud volcanoes and 
lava currents from craters of eruptions, and even in producing 
alterations in the level of the sea.* Large plains and vari- 
ously indented continents are raised or sunk, lands are sep 
arated fi:om seas, and the ocean itself, which is permeated by 
hot and cold currents, coagulates at both poles, converting 
water into dense masses of rock, which are either stratified and 
fixed, or broken up into floating banks. The boundaries of 
sea and land, of fluids and solids, are thus variously and fre- 
quently changed. Plains have undergone oscillatory move- 
ments, being alternately elevated and depressed. After the 
elevation of continents, mountain chains were raised upon long 
fissures, mostly parallel, and, in that case, probably cotem- 
poraneous ; and salt lakes and inland seas, long inhabited by 
the same creatures, were forcibly separated, the fossil remains 
of shells and zoophytes still giving evidence of their original 
connection. Thus, in following phenomena in their mutual 
dependence, we are led from the consideration of the forces 
acting in the interior of the Earth to those which cause erup- 
tions on its surface, and by the pressure of elastic vapors give 
rise to burning streams of lava that flow from open fissures. 

The same powers that raised the chains of the Andes and 
the Himalaya to the regions of perpetual snow, have occa- 
sioned new compositions and new textures in the rocky masses, 
and have altered the strata which had been previously de- 
posited from fluids impregnated with organic substances. We 
here trace the series of formations, divided and superposed ac- 
cording to their age, and depending upon the changes of con- 
figuration of the surface, the dynamic relations of upheaving 
forces, and the chemical action of vapors issuing from the 
fissures. 

The form and distribution of continents, that is to say, of 
that solid portion of the Earth's surface which is suited to the 
luxurious development of vegetable life, are associated by in- 
timate connection and reciprocal action with the encircling 

* [See Daubeney On Volcanoes, 2d edit., 1848, p. 539, &c., on the so- 
called mui volcanoes, and the reasons advanced in favor of adopting the 
term "salses" to designate these phenomena.] — Tr. 



162 uosmorj. 

sea, in which organic life is almost entirely limited to the ani- 
mal world. The liquid element is again covered by the at- 
mosphere, an aerial ocean in which the mountain chains and 
high plains of the dry land rise like shoals, occasioning a va- 
riety of currents and changes of temperature, collecting vapor 
from the region of clouds, and distributing life and motion by 
the action of the streams of water which flow from their de- 
clivities. 

While the geography of plants and animals depends on 
these intricate relations of the distribution of sea and land, the 
configuration of the surface, and the direction of isothermal 
lines (or zones of equal mean annual heat), we find that the 
case is totally different when we consider the human race — 
the last and noblest subject in a physical description of the 
globe. The characteristic differences in races, and their rela- 
tive numerical distribution over the Earth's surface, are con- 
ditions affected not by natural relations alone, but at the same 
time and specially, by the progress of civilization, and by moral 
and intellectual cultivation, on Mdiich depends the political 
superiority that distinguishes national progress. Some few 
races, clinging, as it were, to the soil, are supplanted and ruined 
by the dangerous vicinity of others more civilized than them- 
selves, until scarce a trace of their existence remains. Other 
races, again, not the strongest in numbers, traverse the liquid 
element, and thus become the first to acquire, although late, 
a geographical knowledge of at least the maritime lands of the 
whole surface of our globe, from pole to pole. 

I have thus, before we enter on the individual characters 
of that portion of the delineation of nature which includes the 
sphere of telluric phenomena, shown generally in what man- 
ner the consideration of" the form of the Earth and the inces- 
sant action of electro-magnetism and subterranean heat may 
enable us to embrace in one view the relations of horizontal 
expansion and elevation on the Earth's surface, the geognostic 
type of formations, the domam of the ocean (of the liquid por- 
tions of the Earth), the atmosphere with its meteorological 
processes, the geographical distribution of plants and animals, 
and, finally, the physical gradations of the human race, which 
is, exclusively and every where, susceptible of intellectual cul- 
ture. This unity of contemplation presupposes a connection 
of phenomena according to their internal combination. A 
mere tabular arrangement of these facts would not fulfill the 
object I have proposed to myself, and would not satisfy that 
requiren\ent for cosraical presentation awakened in me by the ' 



I 



FKiUllK OF THE EARTlf. 163 

aspect of nature in my journeyings by sea and land, by the 
careful study of forms and forces, and by a vivid impression 
of the unity of nature in the midst of the most varied portions 
of the Earth. In the rapid advance of all branches of physical 
science, much that is deficient in this attempt will, perhaps, 
at no remote period, be corrected, and rendered more perfect, 
for it belongs to the history of the development of knovt^ledge 
that portions which have long- stood isolated become gradually 
connected, and subject to higher laws. I only indicate the 
empirical jiath in which I and many others of similar pursuits 
with myself are advancing, full of expectation that, as Plato 
tells us Socrates once desired, " Nature may be interpreted by 
reason alone."* 

The delineation of the principal characteristics of telluric 
phenomena must begin with the form of our planet and its 
relations in space. Here, too, we may say that it is not only 
the mineralogical character of rocks, whether they are crys- 
talline, granular, or densely fossiliferous, but the geometrical 
form of the Earth itself, which indicates the mode of its origin, 
and is, in fact, its history. An elliptical spheroid of revolu- 
tion gives evidence of having once been a soft or fluid mass. 
Thus the Earth's compression constitutes one of the most an- 
cient geognostic events, as every attentive reader of the book 
of nature can easily discern ; and an analogous fact is pre- 
sented in the case of the Moon, the perpetual direction of whose 
axes toward the Earth, that is to say, the increased accumula- 
tion of matter on that half of the Moon which is turned to- 
ward us, determines the relations of the periods of rotation and 
revolution, and is probably cotemporaneous with the earliest 
epoch in the formative history of this satellite. The mathe- 
matical figure of the Earth is that which it would have were 
its surface covered entirely by water in a state of rest ; and it 
is this assumed form to which all geodesical measurements of 
decrees refer. This mathematical surface is difi'ereiit from 
that true physical surface which is alTected by all the acci- 
dents and inequalities of the solid parts. f The whole figure 
of the Earth is determined when we know the amount of the 

* Plato, Phccdo, p. 97. (Arist., Metaph., p. 985.) Compare Hegel, 
Philosophic der Geschichte, 1840, s. 16. 

t Bessel, Allgemeine Betrachtungen uber Gradmessungeri nach astro- 
nomisch-geoddtischen Arbeiten, at the conclusion of Bessel and Baeyer, 
Gradmessung in Ostpreussen, s. 427. Regarding the accumulation ot" 
matter on the side of the Moon turned toward us (a subject noticed 
in an earlier part (jf the text), see Laplace, Expos, du Syst. du Monde, 
p. 308. 



164 ' COSMOS. 

compression at the poles and the equatorial diameter ; m or- 
der, however, to obtain a perfect representation of its form it 
is necessary to have measurements in two directions, perpen- 
dicular to one another. 

Eleven measurements of degrees (or determinations of the 
curvature of the Earth's surface in diflerent parts), of which 
nine only belong to the present century, have made us ac- 
quainted with the size of our globe, which Pliny named " a 
point in the immeasurable universe."* If these measurements 
do not always accord in the curvatures of different meridians 
under the same degree of latitude, this very circumstance 
speaks in favor of the exactness of the instruments and the 
methods employed, and of the accuracy and the fidelity to 
nature of these partial results. The conclusion to be drawn 
from the increase of forces of attraction (in the direction from 
the equator to the poles) with respect to the figure of a planet 
is dependent on the distribution of density in its interior. 
Newton, from theoretical principles, and perhaps likewise 
prompted by Cassini's discovery, previously to 1666, of the 
compression of Jupiter,! determined, in his immortal work, 
PhiLoso2:)hice Naturalis Principia, that the compression of the 
Earth, as a homogeneous mass, was -^^-^Xh.. Actual meas- 

* Plin., ii., 68. Seneca, Nat. Qucest., Prcef., c. ii. " El mundo as 
poco" (the Earth is small and narrow), writes Columbus from Jamaica 
to Queen Isabella on the 7th of July, 1503 ; not because he entertained 
the philosophic views of the aforesaid Romans, but because it appeared 
advantageous to him to maintain that the journey from Spain w^as not 
long, if, as he observes, " we seek the east from the west." Compare 
my Examen Crit. de VHist. de la Geogr. dn 15me Siecle, t. i., p. 83, and 
t. ii., p. 327, where I have shown that the opinion maintained by De- 
lisle, Fr6ret, and Gosselin, that the excessive differences in the state- 
ments regarding the Earth's circumference, found in the writings of 
the Greeks, are only apparent, and dependent on different values being 
attached to the stadia, was put forward as early as 1495 by Jaime Fer- 
rer, in a proposition regai'ding the determination of the line of demark- 
ation of the papal dominions. 

t Brewster, Life of Sir Isaac Newton, 1831, p. 162. " The discovery 
of the spheroidal form of Jupiter by Cassini had probably directed the 
attention of Newton to the determination of its cause, and, consequent- 
ly, to the investigation of the true figure of the Earth." Although Cas- 
sini did not announce the amount of the compression of Jupiter (—jth) 
till 1691 (Anciens MSmoires de V Acad, des Sciences, t. ii., p. 108), yet 
we know from Lalande (Astron., 3me ed., t. iii., p. 335) that Moraldi 
possessed some printed sheets of a Latin work, " On the Spots of the 
Planets," commenced by Cassini, from which it was obvious that he 
was aware of the compression of Jupiter before the year 1666, and 
therefore at least twenty-one yeai's before the publication of Newton's 
Principia. 



FIGURE OF THE EARTH. 165 

urements, made by the aid of new and more perfect analysis, 
have, however, shown that the compression of the poles of the 
terrestrial spheroid, when the density of the strata is regarded 
as increasing toward the center, is very nearly g^o^h. 

Three methods have been employed to investigate the curv- 
ature of the Earth's surface, viz., measurements of degrees, 
oscillations of the pendulum, and observations of the inequal- 
ities in the Moon's orbit. The first is a direct geometrical 
and astronomical method, while in the other two we determ- 
ine from accurately observed movements the amount of the 
forces which occasion those naovements, and from these forces 
we arrive at the cause from whence they have originated, viz., 
the compression of our terrestrial spheroid. In this part of 
my delineation of nature, contrary to my usual practice, I 
have instanced methods because their accuracy affords a strik- 
ing illustration of the intimate connection existing among 
the forms and forces of natural phenomena, and also because 
their application has given occasion to improvements in the 
exactness of instruments (as those employed in the measure- 
ments of space) in optical and chronological observations ; to 
greater perfection in the fundamental branches of astronomy 
and mechanics in respect to lunar motion and to the resistance 
experienced by the oscillations of the pendulum ; and to the 
discovery of new and hitherto untrodden paths of analysis. 
With the exception of the investigations of the parallax of 
stars, which led to the discovery of aberration and nutation, 
the history of science presents no problem in which the ob- 
ject attained — the knowledge of the compression and of the 
irregular form of our planet — is so far exceeded in importance 
by the incidental gain which has accrued, through a long and 
weary course of investigation, in the general furtherance and 
improvement of the mathematical and astronomical sciences. 
The comparison of eleven measurements of degrees (in which 
are included three extra-European, namely, the old Peruvian 
and two East Indian) gives, according to the most strictly 
theoretical requirements allowed for by Bessel,*" a compression 

* According to Bessel's examination of ten measurements of degrees, 
in which the error discovered by Puissant in the calculation of the 
French measurements is taken into consideration (Schumacher, Astron. 
Nackr., 1841, No. 438, s. 116), the semi-axis major of the elliptical 
spheroid of revolution to which the irregular figure of the Earth most 
closely approximates is 3,272,077-14 toises, or 20,924,774 feet; the semi- 
axis minor, 3,261,159-83 toises, or 20,854,821 feet; and the amount of 
compression or eccentricity _^_^_-j.^d ; the length of a mean degree of 
the meridian, 57,013-109 tofses, or 364,596 feet, with an error of -\- 



166 coriiVios. 

of -g-g-g-tli. In accordance with this, the polar radius is 1 0,938 
toises (69,944 feet), or about 11|- miles, shorter than the equa- 
torial radius of our terrestrial spheroid. The excess at the 
equator in consequence of the curvature of the upper surface 
of the globe amounts, consequently, in the direction of gravi- 
tation, to somevv^hat more than 4^th times the height of 
Mont Blanc, or only 21 times the probable height of the 
summit of the Dhawalagiri, in the Himalaya chain. The 
lunar inequalities (perturbation in the moon'^s latitude and 
longitude) give, according to the last investigations of Laplace, 
almost the same result for the eUipticity as the measurements 
of degrees, viz., 2-y¥^h. The results yielded by the oscillation 
of the pendulum give, on the whole, a much greater amount 
of compression, viz., •gjs'th.* 

2-8403 toises, or 18-16 feet, whence the leugtli ofja geographical mile 
is 3807-23 toises, or 6086-7 feet. Previous combinations of measure- 
ments of degrees varied betvi^een gl^d and g^^th; thus Walbeck (Z>e 
Forma et Magnitudine telluris in demensis arcubus Meridiani definiendis, 
1819) gives 3 Q^ij^th : Ed. Schmidt {Lekrhichder Maikem. und Phi/s. Geo- 
graphie, 1829, s. 5) gives -ggl^- 2d, as tlie mean of seven measures. Re- 
specting the influence of great differences of longitude on the polar 
compression, see Bibliotheqne Universelle, t. xxxiii., p. 181, and t. xxxv., 
p. 56 ; likev^^ise Connaissance des Term, 1829, p. 290. From the lunar 
inequalities alone, Laplace {Expositioyi du Syst. dn Monde, p. 229) found 
it, by tiie older tables of Biirg, to be «'y^th ; and subsequently, from 
the hmar observations of Burckhardt and Bouvard, he fixed it at ■, g^.yth 
(M^canique Cileste, t. v., p. 13 and 43). 

* The oscillations of the pendulum give ^^^^th as the general result 
of Sabine's great expedition (1822 and 1823, from the equator to 80° 
north latitude) ; according to Freycinet, g^^^.-^d, exclusive of the experi- 
ments instituted at the Isle of France, Guam, aiad Mowi (Mawi); ac- 
cording to Forster, ^^^th ; according to Duperrey, ^^^th ; and ac- 
cording to Liitke ('Partie Nautique, 1836, p. 232), -o^gth, calculated 
from eleven stations. On the other hand, Mathieu ( Connaiss. des Temps, 
1816, p. 330) fixed the amount at ^^_d, from observations made be- 
tween Formentera and Dunkirk; and Biot, at —yth, from observations 
between Formentera and the island of Unst. Compare Baily, Report 
on Pendulum Experiments, in the Memoirs of the Royal Astronomical 
Society, vol. vii., p. 96; also Borenius, in the Bulletin de V Acad, de St. 
Pitersbourg, 1843, t. i., p. 2.5. The first proposal to apply the length of 
the pendulum as a standard of measure, and to establish the third part 
of the seconds pendulum (then supposed to be every where of equal 
length) as a pes horarius, or general measure, that might be recovered 
at any age and by all nations, is to be found in Huygens's Horologium 
Oscillatorium, 1673, Prop. 2.5. A similar wish was afterward publicly 
expressed, in 1742, on a monument erected at the equator by Bouguer, 
La Condamine, and Godin. On the beautiful marble tablet which ex- 
ists, as yet uninjured, in the old Jesuits' College at Quito, I have myself 
read the inscription, Penduli simplicis (pquinoctialis unius minuti secundt 



FIGURE OF THE EARTH. 167 

Galileo, who first observed when a boy (having, probably, 
suffered his thoughts to wander from the service) that the 
height of the vaulted roof of a church might be measured by 
the time of the vibration of the chandeliers suspended at dif- 
ferent altitudes, could hardly have anticipated that the pendu- 
lum would one day be carried from pole to pole, in ordof to 
determine the form of the Earth, or, rather, that the unequal 
density of the strata of the Earth affects the length of the sec- 
onds pendulum by means of intricate forces of local attraction, 
which are, however, almost regular in large tracts of land. 
These geognostic relations of an instrument intended for the 
measurement of time — this property of the pendulum, by 
which, like a sounding line, it searches unknown depths, and 
reveals in volcanic islands,=^ or in the declivity of elevated con- 
tinental m.ountain chains,! dense masses of basalt and mela- 

archetypus, meyisurce naturalis exemplar, niinam universalis ! From an 
observation made by La Condamine, in his Journal du Voyage a I'Equa- 
teur, 1751, p. 163, regarding parts of the inscription that were not tilled 
up. and a slight difference between Bougner and himself respecting the 
numbers, I was led to expect that I should tind considerable discrepan- 
cies between the marble . tablet and the inscription as it had been de- 
scribed in Paris; but, after a careful comparison, I mei'ely found two 
perfectly unimportant ditfereuces ; "ex arcu graduum Sj^" instead of 
"ex arcu graduum plusquam trium," and the date of 1745 instead of 
1742. The latter circumstance is singular, because La Condamine re- 
turned to Europe in November, 1744, Bouguer in June of the same year, 
and Godin had left South America in July, 1744. The most necessary 
and useful amendment to the numbers on this inscription would have 
been the astronomical longitude of Quito. (Humboldt, Ttecueil d'Ob- 
serv. Astroji., t. ii., p. 319-354.) Nonet's latitudes, engraved on Egyp- 
' tian monuments, offer a more recent example of the danger presented 
by the grave perpetuation of false or careless results. 

* Respecting the augmented intensity of the attraction of gravitation 
in volcanic islands (St. Helena, Ualan, Fernando de Noronha, Isle of 
France, Guam, Mowi, and Galapagos), Rawak (Liitke, p. 240) being 
an exception, probably in consequence of its proximity to the high 
land of New Guinea, see Mathieu, in Delambre, Hist, de VAstronomie, au 
ISwe Steele, p. 701. 

t Numerous observations also show great irregularities iu the length 
of the pendulum in the midst of continents, and which are ascribed to 
local attractions. (Delambre, Mesure de la Miridienne, t. iii., p. 548; 
Blot, in the M6m. de V Acad6mie des Sciences, t. viii., 1829, p. 18 and 
23.) In passing over the South of France and Lombardy from west to 
east, we find the minimum intensity of gravitation at Bordeaux ; from 
thence it increases rapidly as we advance eastward, through Figeac, 
Clermont-Ferrand, Milan, and Padua; and in the last town we find that 
the intensity has attained its maximum. The influence of the southern 
declivities of the Alps is not merely dependent on the general size of 
their mass, but (much more), in the opinion of Elie de Beaumont (Reck, 
sitr les R6vol. de la Surface d>i Globe, 1830, p. 729). on the rocks of 
meJaphyie and serpentiue. which have elttviited the cliain. On the 



168 COSMOS. 

phyre instead of cavities, render it difficult, notwithstandmg 
the admirable simplicity of the method, to arrive at any great 
result regarding the figure of the Earth from observation of 
the oscillations of the pendulum. In the astronomical part of 
the determination of degrees of latitude, mountain chains, or 
the denser strata of the Earth, likewise exercise, although in a 
less degree, an unfavorable influence on the measurement. 

As the form of the Earth exerts a powerful influence on the 
motions of other cosmical bodies, and especially on that of its 
own neighboring satellite, a more perfect knowledge of the mo- 
tion of the latter will enable us reciprocally to draw an infer- 
ence regarding the figure of the Earth. Thus, as Laplace ably 
remarks,* "An astronomer, without leaving his observatory, 
may, by a comparison of lunar theory with true observations, 
not only be enabled to determine the form and size of the 
Earth, but also its distance from the Sun and Moon — results 
that otherwise could only be arrived at by long and arduous 
expeditions to the most remote parts of both hemispheres." 

declivity of Ararat, which with Caucasus may be said to lie iii the cen- 
ter of gravity of the old continent formed by Europe, Asia, and Africa, 
the very exact pendulum experiments of Fedorow give indications, not 
of subterranean cavities, but of dense volcanic masses. (Parrot, Reise 
zum Ararat, bd. ii., s. 143.) In the geodesic operations of Carlini and 
Plana, in Lombardy, differences ranging from 20" to 47"-8 have been 
found between direct observations of latitude and the results of these 
operations. (See the instances of Andrate and Mondovi, and those of 
Milan and Padua, in the Operations Geodes. et Astron. potir la Mesure 
d'un Arc du Parallele Moyen, t. ii., p. 347 ; Effemeridi Astron. di Mi- 
lano, 1842, p. 57.) The latitude of Milan, deduced from that of Berne,, 
according to the French triangulation, is 45° 27' 52", while, according 
to direct astronomical observations, it is 45° 27' 35". As the perturba- 
tions extend in the plain of Lombardy to Parma, which is far south of 
thePo (Plana, Op6rat. Geod., t. ii., p. 847), it is probable that there are 
deflecting causes concealed beneath the soil of the plain itself. Struve 
has made similar experiments [ with corresponding results] in the most 
level parts of eastern Europe. (Schumacher, Astron. Nachrichten, 1830, 
No. 164, s. 399.) Regai'ding the influence of dense masses supposed to 
lie at a small depth, equal to the mean height of the Alps, see the ana- 
lytical expressions given by Hossard and Rozet, in the Comptes Rendus, 
t. xviii., 1844, p. 292, and compare them with Poisson, Traiti dc M6- 
caniqjie (2me ed.), t. i., p. 482. The earliest observations on the in- 
fluence which dinerent. kinds of I'ocks exercise on the vibration of ihe 
pendulum are those of Thomas Young, in the Philos. Transactions for 
1819, p. 70-96. In drawing conclusions regarding the Earth's curva- 
ture from the length of the pendulum, we ought not to overlook the 
possibility that its crust may have undergone a process of hardening 
previously to metallic and dense basaltic masses having penetrated froc3 
great depths, through open clefts, and approached near the surface. 
* Laplace, Expos, du Syst. du Monde, p. 231. 



DENSITY OF THE EARTH. 169 

The compression which may be inferred from lunar inequali- 
ties affords an advantage not yielded by individual measure- 
ments of degrees or experiments w^ith the pendulum, since it 
gives a mean amount which is referable to the whole planet. 
The comparison of the Earth's compression with the velocity 
of rotation . shows, further, the increase of density from the 
strata from the surface toward the center — an increase which 
a comparison of the ratios of the axes of Jupiter and Saturn 
with their times of rotation likewise shows to exist in these 
two large planets. Thus the knowledge of the external form 
of planetary bodies leads us to draw conclusions regarding their 
internal character. 

Th# northern and southern hemispheres appear to present 
nearly the same curvature under equal degrees of latitude, but, 
as has already been observed, pendulum experiments and 
measurements of degrees yield such different results for indi- 
vidual portions of the Earth's surface that no regular figure 
can be given which would reconcile all the results hitherto 
obtained by this method. The true figure of the Earth is to 
a regular figure as the uneven surfaces of water in motion are 
to the even surface of water at rest. 

When the Earth had been measured, it still had to bo 
weighed. The oscillations of the pendulum* and the plum- 
met have here likewise served to determine the mean density 
of the Earth, either in connection with astronomical and geo- 
detic operations, with the view of finding the deflection of the 
plummet from a vertical line in the vicinity of a mountain, or 
by a comparison of the length of the pendulum in a plain and 
on the summit of an elevation, or, finally, by the employment 
of a torsion balance, which may be considered as a horizon- 
tally vibrating pendulum for the measurement of the relative 
density of neighboring strata. Of these three methods! the 

* La Caille's pendulum measurements at the Cape of Good Hope, 
which have been calculated with much care by Mathieu (Delarabre, 
Hist, de VAstr-on. an ISme Siecle, p. 479), give a compression of ^^j-.^^th; 
but, from several comparisons of observations made in equal latitudes 
in the two hemispheres (New HoUmid and. the Malouines (Falkland 
Islands), compared with Barcelona, New York, and Dunkirk), there is 
»as yet no reason for supposing that the mean compression of the south- 
ern hemisphere is greater than that oithe northern. (Blot, in the M6in. 
de VAcad. des Sciences, t. viii., 1829, p. 39-41.) 

t The three methods of observation give the ibllowing results: (1.) by 
the deflection of the plumb-line in the proximity of the Shehallieu 
Mountain (Gaelic, Thichallin) in Perthshire, 4-713, as determined by 
Maskelyne, Kutton, and Playfair (1774-1776 and 1810), according to a 
method that had been proposed by Newton; (2.) by pendulum vibra 

Vol. I — H 



170 " COSMOS. 

last IS the most certain, since it is independent of the difficult 
determination of the density of the mineral masses of which 
the spherical segment of the mountain consists near which the 
observations are made. According to the most recent experi- 
ments of Reich, the result obtained is 5'44 ; that is to say, the 
mean density of the whole Earth is 5-44 times gireater than 
that of pure water. As, according to the nature of the min- 
eralogical strata constituting the dry continental part of the 
Earth's surface, the mean density of this portion scarcely 
amounts to 2*7, and the density of the dry and liquid surface 
conjointly to scarcely 1*6, it follows that the elliptical un- 
equally compressed layers of the interior must greatly increase 
m density toward the center, either through pressure or^owing 
to the heterogeneous nature of the substances. Here again 
we see that the vertical, as well as the horizontally vibrating 
pendulum, may justly be termed a geognostical instrument. 

The results obtained by the employment of an instrument 
ol" this kind have led celebrated physicists, according to the 
difference of the hypothesis from which they started, to adopt 

tions ou niountaiiis, 4*837 (Carlini's observations on Mount Cenis coni^ 
pared with Biot's observations at Bordeaux, Effemer. Astron. di Milano, 
1824, p. 184); (3.) by the torsion balance used by Cavendish, with an 
ap{)aratus originally devised by Mitchell, 5*48 (according to Hutton's 
revision of the calculation, 5*32, and according to that of Eduai'd 
Schmidt, 5*52; Lehrbitch der Math. Geographic, bd. i., s. 487); by the 
torsion balance, according to Reich, 5-44, In the calculation of these 
experiments of Professor Reich, which have been made with masterly 
accuracy, the original mean result was 5-43 (with a probable error of 
only 0233), a result which, being increased by the quantity by which 
the Earth's centrifugal force diminishes the force of gravity for the lati- 
tude of Freiberg (50"^ 55'), becomes changed to 5*44. The employ- 
ment of cast iron instead of lead has not presented any sensible differ- 
ence, or none exceeding the limits of errors of observation, hence dis- 
closing no traces of magnetic influences. (Reich, Versjiche uberdie mitt- 
lere Dichtigheit der Erde, 1838, s. 60, 62, and QQ.) By the assumption 
of too slight a degree of ellipticity of the Earth, and by the uncertainty 
of the estimations regarding the density of rocks on its surface, the 
mean density of the Earth, as deduced from exiieriments on and near 
mountains, was found about one sixth smaller than it really is, name- 
ly, 4-761 (Laplace, Mican. CHesfe, t. v., p. 46), or 4-783. (Eduard 
Schmidt, Lehrh. der Math. Geogr., bd. i., ^ 387 uud 418.)' On Halley's 
hypothesis of the Earth being a hollow sphere (noticed ia page 171), 
which was the germ of Franklin's ideas concerning earthquakes, see 
Philos. Trans, for the year 1693, vol. xvii., p. 563 {On the Structure of 
the laternal Parts of the Earth, and the concave habited Arch of the 
Shell). Halley regarded it as more worthy of the Creator " that tlio 
Earth, like a house of several stories, should be inhabited both without 
and within. For light in the hullovv sphere (p. 576) provision might ii* 
Bome manner be contrived." 



DENSITY OF THE EARTH. 171 

entirely opposite views regarding the nature of the interior of 
the globe. It has been computed at what depths liquid or 
even gaseous substances would, from the pressure of their 
own superimposed strata, attain a density exceeding that of 
platinum or even iridium ; and in order that the compression 
which has been determined within such narrow limits migh* 
be brought into harmony with the assumption of simple and 
infinitely compressible matter, Leslie has ingeniously conceived 
the nucleus of the world to be a hollow sphere, filled with an 
assumed " imponderable matter, having an enormous force of 
expansion." These venturesome and arbitrary conjectures 
have given rise, in wholly unscientific circles, to still more 
fantastic notions. The hollow sphere has by degrees been 
peopled with plants and animals, and two small subterranean 
revolving planets — Pluto and Proserpine — were imaginatively 
supposed to shed over it their mild light ; as, however, it was 
further imagined that an ever-uniform temperature reigned in 
these internal regions, the air, which was made self-luminous 
by compression, might well render the planets of this lower 
world unnecessary. Near the north pole, at 82° latitude, 
whence the polar light emanates, was an enormous opening, 
through which a descent might be made into the hollow 
sphere, and Sir Humphrey Davy and myself were even pub- 
licly and frequently invited by Captain Symmes to enter upon 
this subterranean expedition : so powerful is the morbid in- 
clination of men to fill unknown spaces with shapes of won- 
der, totally unmindful of the counter evidence furnished by 
well-attested facts and universally acknowledged natural laws. 
Even the celebrated Halley, at the end of the seventeenth 
century, hollowed out the Earth in his magnetic speculations I 
Men were invited to believe that a subterranean freely-ro- 
tating nucleus occasions by its position the diurnal and an- 
nual changes of magnetic declination. It has thus been at- 
tempted in our own day, with tedious solemnity, to clothe in 
a scientific garb the quaintly-devised fiction of the humorous 
Ilolberg.* 

* [The work referred to, one of the wittiest prodnctions of tlie learned 
Norwegian satirist and dramatist Holberg, was written in Latin, and 
first appeared under the following title : Nicolai Klimii Her suhterra- 
neum novum tellvris theonam ac historiam qr/intce monarchice adhuc «o- 
his incogvAtce exhibens e hibliotheca b. Abelini. Hafniee ct Lipsice snmt. 
Jac. Prenss, 1741. An admirable Danish translation of this learned 
but severe satire on the institutions, morals, and manners of the inhab* 
itants of the upper Earth, appeared at Copenhagen in 1789, and was 
entitled Niels Klim^s ujiderjordiske reise ved Lndwig Holberg, oversat 



172 COSMOS. 

The figure of the Earth and the amount of solidification 
(density) w^hich it has acquired are intimately connected with 
the forces by which it is animated, in so far, at least, as they 
have been excited or awakened from without, through its 
planetary position with reference to a luminous central body. 
Compression, when considered as a consequence of centrifugal 
force acting on a rotating mass, explains the earUer condition 
of fluidity of our planet. During the solidification of this 
fluid, which is commonly conjectured to have been gaseous 
and primordially heated to a very high temperature, an enor- 
mous quantity of latent heat must have been liberated. If 
the process of solidification began, as Fourier conjectures, by 
radiation from the cooling surface exposed to the atmosphere, 
the particles near the center would have continued fluid and 
hot. As, after long emanation of heat from the center toward 
the exterior, a stable condition of the temperature of the 
Earth would at length be established, it has been assumed 
that with increasing depth the subterranean heat likewise 
uninterruptedly increases. The heat of the water which 
flows from deep borings (Artesian wells), direct experiments 
regarding the temperature of rocks in mines, but, above all, 
the volcanic activity of the Earth, shown by the flow of molt- 
en masses from open fissures, afibrd unquestionable evidence 
of this increase for very considerable depths from the upper 
strata. According to conclusions based certainly upon mere 
analogies, this increase is probably much greater toward the 
center. 

That which has been learned by an ingenious analytic cal- 
culation, expressly perfected for this class of investigations,* 

efter den Latinske original af Jens Baggesen. Holberg, who studied 
for a time at Oxford, was born at Bergen in 1685, and died in 1754 as 
Rector of the University of Copenhagen.] — Tr. 

* Here we must notice the admirable analytical labors of Fourier, 
Biot, Laplace; Poisson, Duhamel, and Lame. In his Th6orie Mathema- 
tique de la Chaleur, 1835, p. 3, 428-430, 436, and 521-524 (see, also, 
De la Rive's abstract in the Bibliotheque Universelle de Geneve), Pois- 
son has developed an hypothesis totally different from Fourier's view 
( Theorie Analytique de la Chaleur.) He denies the present fluid state 
of the Earth's center ; he believes that " in cooling by radiation to the 
medium surrounding the Earth, the parts which were first solidified 
Bunk, and that by a double descending and ascending current, the great 
inequality was lessened which would have taken place in a solid body 
cooling from the surface." It seems more probable to this great ge- 
ometer that the solidification began in the parts lying nearest to the 
center : " the phenomenon of the increase of heat with the depth does 
not extend to the whole mass of the Earth, and is merely a consequence 
of the motion of our planetary system in space, of which some parts 



INTERNAL HEAT OF THE EARTH. 173 

reguiding the motion of heat in homogeneous metallic sphe- 
roids, must be applied with much caution to the actual char- 
acter of our planet, considering our present imperfect knowl- 
edge of the substances of which the Earth is composed, the 
difference in the capacity of heat and in the conducting power 
of different superimposed masses, and the chemical changes 
experienced by solid and liquid masses from any enormous 
compression. It is with the greatest difficulty that our pow- 
ers of comprehension can conceive the boundary line which di- 
vides the fluid mass of the interior from the hardened mineral 
masses of the external surface, or the gradual increase of the 
solid strata, and the condition of semi-fluidity of the earthy 
substances, these being conditions to which known laws of 
hydraulics can only apply under considerable modifications. 
The Sun and Moon, which cause the sea to ebb and flow, 
fliost probably also affect these subterranean depths. We 
may suppose that the periodic elevations and depressions of 
the molten mass under the already solidified strata must have 
caused inequalities in the vaulted surface from the force of 
pressure. The amount and action of such oscillations must, 
however, be small ; and if the relative position of the attract- 
ing cosmical bodies raiay here also excite " spring tides," it is 
certainly not to these, but to more powerful internal forces, 
that we must ascribe the movements that shake the Earth's 
surface. There are groups of phenomena to whose existence 
it is necessary to draw attention, in order to indicate the 
universality of the influence of the attraction of the Sun and 
Moon on the external and internal conditions of the Earth, 
however little we may be able to determine the quantity of 
this influence. 

According to tolerably accordant experiments in Artesian 
wells, it ha? been shown that the heat increases on an average 
about 1° foi every 54-5 feet. If this increase can be reduced 

are of a very different temperature from others, iu consequence of stel- 
lar heat (chaleur stellah*e)." Thus, accoi'ding to Poisson, the warmth 
of the water of our Artesian wells is merely that which has penetrated 
into the Earth from without ; and the Earth itself " might be regarded 
as in the same circumstances as a mass of rock conveyed from the 
equator to the pole in so short a time as not to have entirely cooled. 
The .ncrease of temperature in such a block wtiiuld not extend to the 
central strata." The physical doubts which have reasonably been 
entertained against this extraordinary cosmical view (which attributes 
to the regions of space that which probably is more dejieiident on the 
first transition of matter condensing from the gaseo-fluid into the solid 
state) will be found collected in Poggendorf 's Annalen, bd. x.xxix,, a. 
93-100. 



174 COSMOS. 

to arithmetical relations, it will follow, as I have already ob- 
served,* that a stratum of granite would be in a state of fusion 
at a depth of nearly twenty-one geographical miles, or between 
four and five times the elevation of the highest summit of the 
Himalaya. 

We must distinguish in our globe three different modes for 
the transmission of heat. The first is periodic, and affects 
the temperature of the terrestrial strata according as the heat 
penetrates from above downward or from below upward, being 
influenced by the different positions of the Sun and the sea- 
sons of the year. The second is likewise an efiect of the Sun, 
although extremely slow : a portion of the heat that has pene- 
trated into the equatorial regions moves in the interior of the 
globe toward the poles, where it escapes into the atmosphere 
and the remoter regions of space. The third mode of trans- 
mission is the slowest of all, and is derived from the seculaT 
cooling of the globe, and from the small portion of the primi- 
tive heat which is still being disengaged from the surface. 

* See the Introduction. This increase of temperature has been found 

in the Puits de Greuelle, at Paris, at 58'3 feet ; in the boring at the new 

salt-works at Minden, almost 53*6 ; at Pregny, near Geneva, according 

to Auguste de la Rive and Marcet, notwithstanding that the uiouth oi 

the boring is 1609 feet above the level of the seaj it is also 53-6 feet. 

This coincidence between the results of a method first proposed by 

Arago in the year 1821 {Annuaire du Bureau des Longitudes, 1835, p. 

234), for three different mines, of the absolute depths of 1794, 2231, 

and 725 feet respectively, is remarkable. The two points on the Earth, 

lying at a small vertical distance from each other, whose annual mean 

temperatures are most accurately known, are probably at the spot on 

which the Paris Observatory stands, and the Caves de I'Observatoire 

beneath it: the mean temperature of the former is 51'^"5, and of the 

latter 53°-3, the ditference being lo-8 for 92 feet, or 1° for 51-77 feet. 

(Poisson, Thiorie Math, de la Chaleur, p. 415 and 462.) In the course 

of the last seventeen years, from causes not yet perfectly understood, 

but probably not connected with the actual temperature of the caves, 

the thermometer standing there has risen very nearly 0'-'*4. Although 

in Artesian wells there are sometimes slight errors from the lateral 

permeation of water, these errors are less injurious to the accuracy of 

conclusions than those resulting from cuiTents of cold air, which are 

almost always present in mines. The general result of Reich's great 

work on the temperature of the mines in the Saxony mining districts 

gives a somewhat slower increase of the terrestrial heat, or 1° to 76*3 

feet. (Reich, Beob. uber die Te^nperatur des Gesteins in verschieden en 

Tiefen, 1834, s. 134.) Phillips, however, found (Pogg., Annalen, bd. 

xxxiv., s. 191), in a shaft of the coal-mine of Monk-wearmouth, near 

Newcastle, in which, as I have already remarked, excavations are going 

on at a depth of about 1500 feet below the level of the sea, an increase 

of 1° to 59*06 feet, a result almost identical with that found by Arago 

in the Puits de Grenell. 



MEAN TEMPER A TURK OF THE EARTH. 175 

This loss experienced by the central heat must have been very 
considerable in the earliest epochs of the Earth's revolutions, 
but within, historical periods it has hardly been appreciable 
by our instruments. The surface of the Earth is therefore 
situated between the glowing heat of the inferior strata and 
the universal regions of space, whose temperature is probably 
below the freezing-point of mercury. 

The periodic changes of temperature which have been 
occasioned on the Earth's surface by the Sun's position and 
by meteorological processes, are continued in its interior, 
although to a very inconsiderable depth. The slow conduct- 
ing power of the ground diminishes this loss of heat in the 
winter, and is very favorable to deep-rooted trees. Points 
that lie at very different depths on the same vertical line 
attain the maximum and minimum of the imparted tempera- 
ture at very different periods of time. The further they are 
removed from the surface, the smaller is this difference be- 
tween the extremes. In the latitudes of our temperate zone 
(between 48^ and 52°), the stratum of invariable temperature 
is at a depth of from 59 to 64 feet, and at half that depth 
the oscillations of the thermometer, from the influence of the 
seasons, scarcely amount to half a degree. In tropical cli- 
mates this invariable stratum is only one foot below the 
surface, and this fact has been ingeniously made use of by 
Boussingault to obtain a convenient, and, as he. believes, cer- 
tain determination of the mean temperature of the air of 
different places.* This mean temperature of the air at a 
fixed point, or at a group of contiguous points on the surface, 
is to a certaiij degree the fundamental element of the climato 
and agricultural relations of a district ; but the mean tem- 
perature of the whole surface is very different from that of 
the globe itself. The questions so often agitated, whether the 
mean temperature has experienced any considerable differences 
in the course of centuries, whether the climate of a country 
has deteriorated, and whether the winters have not become 
milder and the summers cooler, can only be answered by 
means of the thermometer ; this instrument has, however, 
scarcely been invented more than two centuries and a half, 
and its scientific application hardly dates back 120 years. 
The nature and novelty of the means interpose, therefore, very 
narrow limits to our investigation regarding the temperature 

* Boussingault, Su7- la Profondeur a laqnelle se trouve la Coiiche de 
Temperature invariable entre les Tropiqv.es, in the Annalcf de. Chimin 
et de Physique, t. liii., 1833, p. 225-247. 



176 COSMOS. 

of the air. It is quite otherwise, however, with the solution 
of the great problem of the internal heat of the whole Earth. 
As we may judge of uniformity of temperature from the unal- 
tered time of vibration of a pendulum, so we may also learn, 
from the unaltered rotatory velocity of the Earth, the amount 
of stability in the mean temperature of our globe. This 
msight into the relations between the length of the day and 
the heat of the Earth is the result of one of the most brilliant 
applications of the knowledge we had long possessed of the 
movement of the heavens to the thermic condition of our 
planet. The rotatory velocity of the Earth depends on its 
volume ; and since, by the gTadual cooling of the mass by 
radiation, the axis of rotation would become shorter, the rota- 
tory velocity would necessarily increase, and the length of the 
day diminish, with a decrease of the temperature. From the 
comparison of the secular inequalities in the motions of the 
Moon with the eclipses observed in ancient times, it follows 
that, smc« the time of Hipparchus, that is, for full 2000 
years, the length of the day has certainly not diminished by 
the hundredth part of a second. The decrease of the mean 
heat of the globe during a period of 2000 years has not, there- 
fore, taking the extremest limits, diminished as much as a^gth 
of a degree of Fahrenheit.* 

This invariability of form presupposes also a great invaria- 
bility in the distribution of relations of density in the interior 
of the globe. The translatory movements, which occasion 
the eruptions of our present volcanoes and of ferruginous lava, 
and the filling up of previously empty fissures and cavities 
with dense masses of stone, are consequently dnly to be re- 
garded as slight superficial phenomena afiecting merely one 
portion of the Earth's crust, which, from their smallness 
when compared to the Earth's radius, become wholly insig- 
nificant. 

I have described the internal heat of our planet, both with 
reference to its cause and distribution, almost solely from the 
results of Fourier's admirable investigations. Poisson doubts 
the fact of the uninterrupted increase of the Earth's heat 

* Laplace, Exp. dit, Syst. du Monde, p. 229 and 263 ; Micaniqu6 
Celeste, t. v., p. 18 and 72. It should be remarked that the fraction 
5^th of a degree of Fahrenheit of the mercurial thermometer, given in 
the text as the limit of the stability of the Earth's temperature since 
the days of Hipparchus, rests on the assumption that the dilatation of 
the substances of which the Earth is composed is equal to that of glass. 
that is to say, y^.^o-oth for 1°. Regarding this hypothesis, see Arago 
in the Annuaire for 1834, p. 177-190. 



TERRESTRIAL MAGNETISM. 177 

from the surface to the center, and is of opinion that all heat 
has penetrated from without inward, and that the tempera- 
ture of the globe depends upon the very high or very low 
temperature of the regions of space through- which the solar 
system has moved. This hypotiiesis, imagined by one of the 
most acute mathematicians of our time, has not satisfied phys- 
icists or geologists, or scarcely, indeed, any one besides its au- 
thor. But, whatever mav be the cause of the internal heat 
of our planet, and of its limited or unlimited increase in deep 
strata, it leads us, in this general sketch of nature, through 
the intimate connection of all primitive phenomena of matter, 
and through the common bond by which molecular forces are 
united, into the mysterious domain of magnetism. Changes 
of temperature call forth magnetic and electric currents. Ter- 
restrial magnetism, whose main character, expressed in the 
three-fold manifestation of its forces, is incessant periodic va- 
riabihty, is ascribed either to the heated mass of the Earth 
itself,* or to those galvanic currents which we consider as 
electricity in motion, that is, electricity moving in a closed 
circuit.! 

The mysterious course of the magnetic needle is equally 
affected by time and space, by the sun's course, and by changes 
of place on the Earth's surface. Between the tropics, the 
hour of the day may be known by the direction of the needle 
as well as by the oscillations of the barometer. It is affected 
instantly, but only transiently, by the distant northern light 
as it shoots from the pole, flashing in beams of colored light 
across the heavens. When the uniform horary motion of the 
needle is disturbed by a magnetic storm, the perturbation 
manifests itself simultaneously, in the strictest sense of the 
word, over hundreds and thousands of miles of sea and land, 
or propagates itself by degrees, in short intervals of time, in 

* William Gilbert, of Colchester, whom Galileo pronounced " great 
to a degree that might be envied," said " magnus magnes ipse est globus 
terrestris." He ridicules the magnetic mountains of Frascatori, the great 
cotemporary of Columbus, as being magnetic poles : " rejicienda est 
vulgaris opinio de montibus magneticis, aut rupe aliqua magnetica, aut 
polo phantastico a polo mundi distante." He assumes the declination 
of the magnetic needle at any given point on the surface of the Earth 
to be invariable (variatio uuiuscujusque loci constans est), and refers 
the curvatures of the isogenic lines to the configuration of continents 
and the relative positions of sea basins, wrhich possess a weaker mag- 
netic force than the solid masses rising above the ocean. (Gilbert, de 
Magnate, ed. 1633, p. 42, 98, 152, and 155.) 

t Gauss, Allgemeine Theorie des Erdmagnetismus, in the Resultate aut 
■ den Beob. des Magnet. Vereins, 1838, s. 41, p. 56. 

H 2 



17^ COSMOS. 

every direction over the Earth's surface.* In the former case, 
the simultaneous manifestation of the storm may servCj with- 
in certain hmitations. Hke Jupiter's satelhtes, fire-signals, and 
well-observed falls of shooting stars, for the geographical 
determination of degrees of longitude. We here recognize 
with astonishment that the perturbations of two small mag- 
netic needles, even if suspended at great depths below the 
surface, can measure the distances apart at which they are 
placed, teaching us, for instance, how far Kasan is situated 
east of Gottingen or of the banks of the Seine. There are 
also districts in the earth where the mariner, who has been 
enveloped for many days in mist, without seeing either the 
sun or stars, and deprived of all means of determining the 
tirhe, may know with certainty, from the variations in the 
inclination of the magnetic needle, whether he is at the north 
or the south of the port he is desirous of entering.! 

* There are also perturbations which are of a local character, and 
do not extend themselves far, and are probably less deep-seated. Some 
years ago I described a rare instance of this kind, in which an extraor- 
dinaiy disturbance was felt in the mines at Freiberg, but was not per- 
ceptible at Berlin. {Lettre de M. de Humboldt a Son Altesse Roy ale le 
Due de Sussex- sti7' les moyens propres a perfectionner la Connaissance 
ill Magn6tisme Terrestre, in Becquerel's TraiiS Experimental de VElec- 
tricitS, t. vii., p. 442.) Magnetic storms, which were simultaneously 
felt from Sicily to Upsala, did not extend from Upsala to Alten. (Gauss 
and Weber, Resultate des Magnet. Vereins, 1839, $ 128; Lloyd, in the 
Comptcs Rendus de I' Acad, des Sciences, t. xiii., 1843, Sem. ii., p. 725 
and 827.) Among the numerous examples that have been recently 
observed, of perturbations occurring simultaneously and extending over 
wide portions of the Earth's sm-face, and which are collected in Sabine's 
important work {Observ. on Days of unusual Magnetic Disturbance, 
1843), one of the most i-emarkable is that of the 25th of September, 
1841, which was observed at Toronto in Canada, at the Cape of Good 
Hope, at Prague, and partially in Van Diemen's Land. The English 
Sunday, on which it is deemed sinful, after midnight on Saturday, to 
register an observation, and to follow out the great phenomena of crea- 
tion in their perfect development, interrupted the observatious in Van 
Diemen's Land, where, in consequence of the difference of the longi- 
tude, the magnetic storm fell on the Sunday. {Observ., p. xiv., 78, 85, 
and 87.) 

t I have described, in Lametherie's Journal de Physique, 1804, t. 
lix., p. 449, the application (alluded to in the text) of the jnagnetic in- 
clination to the determination of latitude along a coast naming north 
and south, and which, like that of Chili and Peru, is for a part of the 
year enveloped in mist {gar7ia). In the locality I have just mentioned, 
thi^ application is of the greater importance, because, in consequence 
of the strong current running northward as far as to Cape Parena, navi- 
gators incur a great loss of time if they approach the coast to the north 
of the haven they are seeking. In the South Sea, from Callao de Lima 
harbor to Truxillo, which differ from each other in latitude by 3° 57' 



TERRESTRIAL MAHNETISM. 179 

When the needle, by its sudden disturbance in its horary 
course, indicates the presence of a magnetic storm, we are 
stiJl unfortunately ignorant whether the seat of the disturbing 
cause is to be sought in the Earth itself or in the upper re- 
gions of the atmosphere. If we regard the Earth as a true 
magnet, we are obliged, according to the views entertained 
by Friedrich Gauss (the acute propounder of a general theory 
of terrestrial magnetism), to ascribe to every portion of the 
globe measuring one eighth of a cubic meter (or Sy'^-ths of a 
French cubic foot) in volume, an average amount of magnet- 
ism equal to that contained in a magnetic rod of 1 lb. weight.* 
If iron and nickel, and probably, also, cobalt (but not chrome, 
as has long been believed),! are the only substances which 
become permanently magnetic, and retain polarity from a 
certain coercive force, the phenomena of Arago's magnetism 
of rotation and of Faraday's induced currents show, on the 
other hand, that all telluric substances may possibly be made 
transitorily magnetic. According to the experiments of the 

I have observed a variation of the magnetic inclination amounting to 
9° (centesimal division) ; and from Callao to Guayaquil, which differ in 
latitude by 9° 50', a variation of 23^-5. (See my Relat. Hist., t. iii., 
p. 622.) At Guarmey (10° 4' south lat.), Huaura (11° 3' south lat.), 
and Chancay (11° 32' south lat.), the incHnations are 6°-80, 9°, and 
10°-3.5 of the centesimal division. The determination of position by 
means of the magnetic inclination has this remarkable feature connected 
with it, that where the ship's course cuts the isoclinal line almost per- 
pendicularly, it is the only one that is independent of all determination 
of time, and, consequently, of observations of the sun Or stars. It is 
only lately that I discovered, for the first time, that as eaiiy as at the 
close of the sixteenth century, and consequently hardly twenty years 
after Robert Norman had invented the inclinatorium, William Gilbert, 
in his gi-eat work De Magnete, proposed to determine the latitude by 
the inclination of the magnetic needle. Gilbert {Physiologia Nova de 
Magneie, lib. v., cap. 8, p. 200) commends the method as applicable 
" a^re caliginoso." Edward Wright, in the introduction which he 
added to his master's great work, describes this proposal as " worth 
much gold." As he fell into the same error with Gilbert, of presum 
ing that the isoclinal lines coincided with the geographical parallel 
circles, and that the magnetic and geographical equators were identic- 
al, he did not perceive that the proposed method had only a local and 
very limited application. 

* Gauss and Weber, Resvltate des Magnet. Vereins, 1838, § 31, s. 146. 

+ According to Faraday (London and Edinburgh Philosophical Maga- 
zine, 1836, vol. viii., p. 178), pure cobalt is totally devoid of magnetic 
power. I know, however, that other celebrated chemists (Heinrich 
Rose and Wohler) do not admit this as absolutely certain. If out of 
two cai-efuUy-purified masses of cobalt totally free from nickel, one ap- 
pears altogether non-magnetic (in a state of equilibrium), I think it 
probable that the other owes its m;ignetic property to a want of purity ; 
and this opinion coincides with Faraday's view. 



180 COSMOS. 

h'rst-mentioned of these great physicists, water, ice, glass, and 
carbon affect the vibrations of the needle entirely in the same 
manner as mercury in the rotation experiments.* Almost all 
substances show themselves to be, in a certain degree,' mag- 
netic when they are conductors, that is to say, when a current 
of electricity is passing through them. 

Although the knowledge of the attracting poAver of native 
iron magnets or loadstones appears to be of very ancient date 
among the nations of the West, there is strong historical evi- 
dence in proof of the striking fact that the knowledge of the 
directive power of a magnetic needle and of its relation to 
terrestrial magnetism was peculiar to the Chinese, a people 
living in the extremest eastern portions of Asia. More than 
a thousand years before our era, in the obscure age of Codrus, 
and about the time of the return of the Heraclidse to the Pel- 
oponnesus, the Chinese had already magnetic carriages, on 
which the movable arm of the figure of a man continually 
pointed to the south, as a guide by which to find the way 
across the boundless grass plains of Tartary ; nay, even in the 
third century of our era, therefore at least 700 years before 
the use of the mariner's compass in European seas, Chinese 
vessels navigated the Indian Oceanf under the direction of 
magnetic needles pointing to the south. I have shown, in 
another work, what advantages this means of topographical di- 
rection, and the early knowledge and application of the mag- 
netic needle gave the Chinese geographers over the Greeks 
and Romans, to whom, for instance, even the true direction 
of the Apennines and Pyrenees always remained unknown. $ 

The magnetic power of our globe is manifested on the ter- 
restrial surface in three classes of phenomena, one of which 
exhibits itself in the varying intensity of the force, and the 
two others in the varying direction of the inclination, and in 

* Arago, in the Annales de Cliimie, t. xxxii., p. 214 ; Brewster, Treat- 
ise on Magnetism, 1837, p. Ill; Baumgartner, in the Zeitschrift fur 
Phys. und Mathem., bd. ii., s. 419. 

t Humboldt, Examen Critique de VHist. de la Giographie, t. iii., p. 36. 

X Asie Centrale, t. i., Introduction, p. xxxviii.-xlii. The Western 
nations, the Greeks and the Romans, knew that magnetism could be 
communicated to iron, and that that metal loould retain it for a length of 
time. (" Sola hsec materia ferri vires, a magnate lapide accipit, retinet- 
que longo tempore." Plin., xxxiv., 14.) The great discovery of the ter- 
restrial directive force depended, therefore, alone on this, that no one 
in the West had happened to observe an elongated fragment of magnet- 
ic iron stone, or a magnetic iron rod, floating, by the aid of a piece of 
wood, in water, or suspended in the air by a tbreac], in such a position 
as to admit of free motion. 



TERRESTRIAL MAGNETISM. 181 

the horizontal deviation from the terrestrial meridian of the 
spot. Their combined action may therefore be graphically 
represented by three systems of lines, the isodynaniic, isodinic, 
and isogonic (or those of equal force, equal inclination, and 
equal declination). The distances apart, and the relative po- 
sitions of these moving, oscillating, and advancing curves, do 
not always remain the same. The total deviation (variation 
or declination of the magnetic needle) has not at all changed, 
or, at any rate, not in any appreciable degree, during a vv^hole 
century, at any particular point on the Earth's surface,* as, 
for instance, the western part of the Antilles, or Spitzbergen. 
In like manner, we observe that the isogonic curves, when they 
pass in their secular motion from the surface of the sea to a 
continent or an island of considerable extent, continue for a long 
time in the same position, and become inflected as they advance. 
These gradual changes in the forms assumed by the lines 
in their translatory motions, and which so unequally modify 
the amount of eastern and western declination, in the course 
of time render it difficult to trace the transitions and analogies 
of forms in the graphic representations belonging to different 
centuries. Each branch of a curve has its liistory, but this 
history docs not reach further back among the nations of the 
West than the memorable epoch uf the 13th of September, 
1492, when the re-discoverer of the New World found a line 
of no variation 3*^ west of the meridian of the island ol' Flores, 
one of the Azores. t The whole of Europe, excepting a small 

* A very slow secular progression, or a local invariability of the mag- 
netic declination, prevents the confusion which might arise from terres- 
trial influences in the boundaries of land, when, with an utter disregard 
for the coiTection of declination, estates are, after long intervals, meas- 
ured by the mere application of the compass. " The whole mass of 
West Indian property," says Sir John Herschel, " has been saved from 
the bottomless pit of endless litigation by the invariability of the mag- 
netic declination in Jamaica and the surrounding Archipelago during 
the whole of the last century, all surveys of property there having 
been conducted solely by the compass." See Robertson, in the Philo- 
sophical Transactions for 1806, Part ii., p. 348, On the Permanency of 
the Compass in Jamaica since 1660. In the mother country (England) 
the magnetic declination has varied by fully 14° during that period. 

t I have elsewhere shown that, from the documents which have 
come down to us regarding the voyages of Columbus, we can, with 
much certainty, fix upon three places in the Atlantic line of no declina- 
tion for the 13th of September, 1492, the 21st of May, 1496, and the 
16th of August, 1498. The Atlantic line of no declination at that pe- 
riod ran from northeast to southwest. It then touched the South 
American continent a little east of Cape Codera, while it is now ob- 
served to reach that continent on the northern coast of the Brazils. 
(Humboldt, Examen Critique de VHist. de la Giogr., t. iii., p. 44-48.) 



182 COSMOS. 

part of Russia, has now a western declination, while at the 
close of the seventeenth century the needle first pointed due 
north, in London in 1657, and in Paris in 1669, there being 
thus a difference of twelve years, notwithstanding the small 
distance between these two places. In Eastern Russia, to 
the east of the mouth of the Volga, of Saratow, Nischni-Now- 
gorod, and Archangel, the easterly declination of Asia is ad- 
vancino- toward us. Two admirable observers, Hansteen and 
Adolphus Erman, have made us acquainted with the remark- 
able double curvature of the lines of declination in the vast 
region of Northern Asia ; these being concave toward the 
pole between Obdorsk, on the Oby, and Turuchansk, and con- 
vex between the Lake of Baikal and the Gulf of Ochotsk. In 
this portion of the earth, in northern Asia, between the mount- 
ains of Werchojansk, Jakutsk, and the northern Korea, the 
isogenic lines form a remarkable closed system. This oval 
configuration^ recurs regularly, and over a great extent of the 
South Sea, almost as far as the meridian of Pitcairn and the 
group of the Marquesas Islands, between 20° north and 45° 

From Gilbert's Physiologia Nova de Magnate, we see plainly (and the 
fact is very remarkable) that in 1600 the declination was still null in 
the region of the Azoi'es, just as it had been in the time of Columbus 
(lib. 4, cap. 1). I believe that in my Examen Critique (t. iii., p. 54) 
I have proved from documents that the celebrated line of demarkation 
by which Pope Alexander VI. divided the Western hemisphere between 
Portugal and Spain was not drawn through the most western point of 
the Azores, because Columbus wished to convert a physical into a po- 
litical division. He attached great importance to the zone (raya) " iu 
which the compass shows no variation, where air and ocean, the latter 
covered with pastures of sea-weed, exhibit a peculiar constitution, 
where cooling winds begin to blow, and where [as erroneous observa- 
tions of the polar star led him to imagine] the form (sphericity) of the 
Earth is no longer the same." 

* To determine whether the two oval systems of isogouic lines, so 
singularly included each within itself, will continue to advance for cen- 
turies iu the same inclosed form, or will unfold and expand themselves, 
is a question of the highest interest in the problem of the physical 
causes of terrestrial magnetism. In the Eastern Asiatic nodes the dec- 
lination increases from without inward, while in the node or oval sys- 
tem of the South Sea the opposite holds good ; in fact, at the present 
time, in the whole South Sea to the east of the meridian of Kamt- 
schatka, there is no line where the dechnation is null, or. indeed, in 
which it is less than 2° (Erman. in Pogg., Annal., bd. xxxi., § 129). 
Yet Cornelius Schouten, on Easter Sunday^ 1616. appears to have found 
the declination null somewhere to the southeast of Nnkahiva, in 1.5 '^ 
south lat. and 132° west long., and consequently in the middle of tlie 
present closed isogonal system. (Hanstee'n, Magnet, der Erde, 1819, ^ 
28.) It must not be forgotten, in the midst of all these considerations. 
that we can only follow the direction of the magnetic lines in their 
progress as they ai'e projected upon the surface of the Earth. 



MAGNETISM. 183 

south lat. One would almost be. inclined to refjard this sin- 
gular config-uration of closed, almost concentric, lines of decli- 
nation as the effect of a local character of that portion of the 
globe ; but if, in the course of centuries, these apparently iso- 
lated systems should also advance, we must suppose, as in the 
case ol" all great natural forces, that the phenomenon arises 
from some general cause. 

The horary variations of the declination, which, although 
dependent upon true time, are apparently governed by the 
Sun, as long as it remains above the horizon, diminish in an- 
gular value with the magnetic latitude of place. Near the 
equator, for instance, in the island of Rawak, they scarcely 
amount to three or four minutes, while they are from thirteen 
to fourteen minutes in the middle of Europe. As in the whole 
northern hemisphere the north point of the needle moves from 
east to west on an average from 8^ in the morning until 1^ at 
mid-day, while in the southern hemisphere the same north 
point moves from west to east,* attention has recently been 
drawn, with much justice, to the fact that there must be a 
region of the Earth between the terrestrial and the magnetic 
equator where no horary deviations in the declination are to be 
observed. This fourth curve, which might be called the curve 
of no motio7i, or, rather, the line of no variation of horary 
declination, has not yet been discovered. 

The term magnetic 'poles has been applied to those points 
of the Earth's surface where the horizontal power disappears, 
and more importance has been attached to these points than 
properly appertains to them ;t and in like manner, the curve, 
where the inclination of the needle is null, has been termed 
the magnetic equator. The position of this line and its secular 
change of configuration have been made an object of careful 
investigation in modern times. According to the admirable 
work of Duperrey,$ who crossed the magnetic equator six times 
between 1822 and 1825, the nodes of the two equators, that 
is to say, the two points at whicli the line without inclination 
intersects the terrestrial equator, and consequently passes from 
one hemisphere into the other, are so unequally placed, that 
in 1825 the node near the island of St. Thomas, on the west- 

* Arago, in the Annvaire, 1836, p. 284, and 1840, p. 330-338. 

t Gauss, Allg'. Theorie des Erdmagnet.. § 31. 

X Duperrey, De la Corifiguration de V Equateur Magnitique, in the 
Annales de Chimie, t. xlv., p. 371 and 379. (See, also, Morlet, in the 
M&moires presentis par divers Savans a V Acad. Roy. des Sciences, t. iii., 
p. 132.) 



184 COSMOS. 

ern coast of Africa, was 1881° distant from the node m the 
South Sea, close to the little islands of Gilbert, nearly in the 
meridian of the Viti group. In the beginning of the present 
century, at an elevation of 11,936 feet above the level of the 
sea, I made an astronomical determination of the point (7° 1' 
south lat., 48° 40' west long, from Paris), where, in the in- 
terior of the New Continent, the chain of the Andes is inter- 
sected by the magnetic equator between Quito and Lima. To 
the west of this point, the magnetic equator continues to trav- 
erse the South Sea in the southern hemisphere, at the same 
time slowly drawing near the terrestrial equator. It first pass- 
es into the northern hemisphere a little before it approaches 
the Indian Archipelago, just touches the southern points of 
Asia, and enters the African continent to the west of Socotora, 
almost in the Straits of Bab-el-Mandeb, where it is most dis- 
tant from the terrestrial equator. After intersecting the un- 
known regions of the interior of Africa in a southwest direc- 
tion, the magnetic equator re-enters the south tropical zone in 
the Gulf of Guinea, and retreats so far from the terrestrial 
equator that it touches the Brazilian coast near Os Ilheos, 
north of Porto Seguro, in 15° south lat. From thence to the 
elevated plateaux of the Cordilleras, between the silver mines 
of Micuipampa and Caxamarca, the ancient seat of the Incas, 
where I observed the inclination, the line traverses the whole 
of South America, which in these latitudes is as much a mag- 
netic terra incognita as the interior of Africa. 

The recent observations of Sabine* have shown that the 
node near the island of St. Thomas has moved 4° from east to 
west between 1825 and 1837. It would be extremely im- 
portant to know whether the opposite pole, near the Gilbert 
Islands, in the South Sea, has approached the meridian of the 
Carolinas in a westerly direction. These general remarks will 
be sufficient to connect the different systems of isoclinic non- 
parallel lines with the great phenomenon of equilibrium which 
is manifested in the magnetic equator. It is no small advant- 
age, in the exposition of the laws of terrestrial magnetism, that 
the magnetic equator (whose oscillatory change of form and 
whose nodal motion exercise an influence on the inclination 
of the needle in the remotest districts of the world, in conse- 
quence of the altered magnetic latitudes)! should traverse the 

* See the remarkable chart of isocliuic lines in the Atlantic Ocear 
for the years 1825 and 1837, in Sabine's Contributions to Terrcstria- 
Magnetism, 1840, p. 134. 

\ Huinljoldt, Ucher die seciildre Verdnderung der Magnetischea In- 



MAGNETISM. 185 

ocean throughout its whole course, excepting ahout one fifth, 
and consequently be made so much more accessible, owing to 
the remarkable relations in space between the sea and land, 
and to the means of which we are now possessed for determin- 
ing with much exactness both the declination and the inclina- 
tion at sea. 

We have described the distribution of magnetism on the 
surface of our planet according to the two forms of declination 
and iTiclination ; it now, tlierefore, remains for us to speak of 
the intensity of the force which is graphically expressed by 
isodynamic curves (or lines of equal intensity). The investi- 
gation and measurement of this force by the oscillations of a 
vertical or horizontal needle have only excited a general and 
lively interest in its telluric relations since the beginning of 
the nineteenth century. The application of delicate optical 
and chronometrical instruments has rendered the measure- 
ment of this horizontal power susceptible of a degree of accu- 
racy far surpassing that attained in any other magnetic de- 
terminations. The isogenic lines are the more important in 
their immediate application to navigation, while we find from 
the most recent views that isodynamic lines, especially those 
which indicate the horizontal force, are the most valuable ele- 
ments in the theorv of terrestrial magnetism.* One of the 
earliest facts yielded by observation is, that the intensity of 
the total force increases from the equator toward the pole.t 

clination (On the secular Change in the Magnetic Inclination), in Pogo-., 
Annal., bd. xv., s. 322. 

* Gauss, Resultate der Beob. des Magn. Vereins, 1838, ^ 21; Sabine, 
Report on the Variations of the Magnetic Intensity, p. 63. 

t The following is the histoiy of the discovery of the law that the 
intensity of the force increases (in general) with the magnetic latitude. 
When I was anxious to attach myself, in 1798, to the expedition of 
Captain Baudin, who intended to circumnavigate the globe, I was re- 
quested by Borda, wrho took a warm interest in the success of ray proj- 
ect, to examine the oscillations of a vertical needle in the magnetic me- 
ridian in diflferent latitudes in each hemisphere, in order to determine 
whether the intensity of the force was the same, or whether it varied in 
different places. During my travels in the tropical regions of America, 
I paid much attention to this subject. I observed that the same needle, 
which in tlie space often minutes made 245 oscillations in Paris, 246 in 
the Havana, and 242 in Mexico, performed only 216 oscillations during 
the same period at St. Carlos del Rio Negro (1° 53' north lat. and 80° 
40' west long. Irom Paris), on the magnetic equator, i. e., the hne in 
which the inclination =0 ; in Peru (7° 1' south lat. and 80° 40' west 
long, from Paris) only 211 ; while at Lima (12° 2' south lat.) the num- 
ber rose to 210. I found, in the years intervening between 1799 and 
1803, that the whole force, if we assume it at 1-0000 on the, magnetic 
equator in the Peruvian Andes, between Micuipampa and Caxamarca. 



186 COSMOS. 

The knowledge which we possess of the quantity of" this in 
crease, and of" all the numerical relations of the law of in- 

may be expressed at Paris by 1-3482, in Mexico by 1-3155, in San Carlos 
del Rio Negro by 1-0480, and in Lima by 1-0773. When I developed 
this law of the variable intensity of terrestrial magnetic force, and sup- 
ported it by the numerical value of observations instituted in 104 dif- 
ferent places, in a Memoir read before the Paris Institute on the 2Gth 
Frimaire, An. XIII. (of which the mathematical portion was contributed 
by M. Biot), the facts were regarded as altogether new. It was only 
after the reading of the paper, as Biot expressly states (Lametherie, 
Journal de Physique, t. lix., p. 446, note 2), and as I have repeated in 
the Relation Historique, t. i., p. 262, note 1, that M. de Rossel commu- 
nicated to Biot his oscillation experiments made six years earlier (be- 
tween 1791 and 1794) in Van Diemen's Land, in Java, and in Amboyna. 
These experiments gave evidence of the same law of decreasing force 
in the Indian Archipelago. It must, I think, be supposed, that this ex- 
cellent man, when he wrote his work, v^^as not awai'e of the regularity 
of the augmentation and diminution of the intensity, as before the read- 
ing of my paper he never mentioned this (certainly not unimportant) 
physical law to any of our mutual friends, La Place, Delambre, Prony, 
or Biot. It was not till 1808, four years after my retui-n from America, 
that the observations made by M. de Rossel were published in the Voy' 
age de V Entrecasteaux, t. ii., p. 287, 291, 321, 480, and 644. Up to the 
present day it is still usual, in all the tables of magnetic intensity which 
have been published iti Germany (Hausteen, Magnet, der Erde, 1819, 
s. 71; Gauss, Beob. des Magnet. Vereins, 1838, s. 36-39 ; Erman, Phy- 
eikal. Beoh., 1841, s. 529-579), iu England (Sabine, Report on Magnet. 
Intensity. 1838, p. 43-62 ; Contributions to Terrestrial Magnetism, 1843), 
and in France (Becquerel, Traits de Electr. et de 3Iagnet., t. vii., p. 
354-367), to reduce the oscillations observed in any part of the Earth 
to the standard of force which I found on the magnetic equator iu 
Northern Peru, so that, according to the unit thus arbitranly assumed, 
the intensity of the magnetic force at Paris is put down as 1*348. Tht 
observations made by Lamanoii in the unfortunate expedition of La 
Perouse, during the stay at TenerifFe (1785), and on the voiyage to 
Macao (1787), are still older than those of Admiral Rossel. They were 
sent to the Academy of Sciences, and it is known that they were in the 

Eossession of Condorcet in the July of 1787 (Becquerel, t. vii., p. 320) ; 
ut, notwithstanding the most careful search, they are not now to be 
found. From a copy of a very important letter of Lamanon, now in the 
possession of Captain Duperrey, which was addressed to the then per- 
petual secretary of the Academy of Sciences, but was omitted in the 
narrative of the Voyage de La Pe^-ouse, it is stated " that the attractive 
force of the magnet is less in the tropics than when we approach the 
poles, and that the magnetic intensity deduced from the number of os- 
cillations of the needle of the inclination-compass varies and increases 
with the latitude." If the Academicians, while they continued to ex- 
pect the return of the unfortunate La Perouse, had felt themselves justi- 
fied, in the course of 1787, in publishing a truth which had been inde- 
pendently discovered by no less than three different travelers, the theory 
of terrestrial magnetism would have been extended by the knowledge 
of a new class of observations, dating eighteen years earlier than they 
now do. This simple statement of facts may probably justify the ol> 
Bervations contained in the third volume of my Relation Historique (p 



xMAGNETISM. 187 

tensity affecting the whole Earth, is especially due, since 1819. 
to the unwearied activity of Edward Sabine, who, after hav- 
ing observed the oscillations of the same needles at the Ameri- 
can north pole, in Greenland, at Spitzbergen, and on the coasts 
of Guinea and Brazil, has continued to collect and an'angc 
all the facts capable of explaining the direction of the isody- 
namic lines. I have myself given the first sketch of an isody- 
namic system in zones for a small part of South America 
These lines are not parallel to lines of equal incHnation (iso- 
clinic lines), and the intensity of the force is not at its minimum 
at the magnetic equator, as has been supposed, nor is it even 
equal at all parts of it. If we compare Erman's observations 
in the southern part of the Atlantic Ocean, where a faint zone 
(0-706) extends from Angola over the island of St. Helena to 
the Brazilian coast, with the most recent investigations of the 
celebrated navigator James Clark Ross, we shall find that 
on the surface of our planet the force increases almost in the 
relation of 1 : 3 toward the magnetic south pole, where Vic- 
toria Land extends from Cape Crozier toward the volcano 
Erebus, which has been raised to an elevation of 12,600 ieet 
above the ice.* If the intensity near the magnetic south pole 

615): "The observations on the variation of terresti'ial magnetism, to 
which I have devoted myself for thirty-two years, by means of instru- 
ments which admit of comparison with one another, in America, Europe, 
and Asia, embrace an area extending over 188 degrees of longitude, 
from the frontier of Chinese Dzoungarie to the west of the South Sea 
loathing the coasts of Mexico and Peru, and reaching from 60° north 
lat. to 12° south lat. I regard the discovery of the law of the decre- 
ment of magnetic force from the pole to tlie equator as the most im- 
portant i-esult of my American voyage." Although Tiot absolutely cer- 
tain, it is very probable that Condorcet read Lamanou's letter of July, 
1787, at a meeting of the Paris Academy of Sciences; and sucli a sim- 
ple reading I regard as a sufficient act of publication. {Annvaire dit 
Bureau des Longitudes, 1842, p. 463.) The first recognition of the law 
belongs, therefore, beyond all question, to the companion of La Peiouse ; 
but, long disregarded or forgotten, the knowledge of the law that the 
intensity of the magnetic force of the Earth varied with the latitude, 
did not, I conceive, acquii^e an existence in science until the [)ublica- 
tion of my observations from 1798 to 1804. The object and the length 
of this note will not be indifferent to those who are familiar with the 
recent history of magnetism, and the doubts that have been started in 
connection with it, and who, from their own experience, are aware 
that w^e are apt to attach some value to that which has cost us the un- 
interrupted labor of five yeai's, under the pressure of a tropical climate, 
and of perilous mountain expeditions. 

* From the observations hitherto collected, it appears that the max- 
imum of intensity for the wliole surfoce of tlie Earth is 2*052, and the 
minimum 0.706. Both phenomena occur in the southern hemisphere; 
^e former in 73° 47' S. lat., and 169° 30' E. long, from Paris, ueai 



1H8 COSMOS. 

be expressed by 2-052 (the unit still employed being the in-* 
tensity which I discovered on the magnetic equator in North- 
ern Peru), Sabine found it was only 1-624 at the magnetic 
north pole near Melville Island (74° 27' north lat.), while it 
is 1-803 at New York, in the United States, which has al- 
most the same latitude as Naples. 

The brilliant discoveries of QErsted, Arago, and Faraday 
have established a more intimate connection between the elec- 
tric tension of the atmosphere and the magnetic tension of our 
terrestrial globe. While CErsted has discovered that elec- 
tricity excites magnetism in the neighborhood of the conduct- 
ing body, Faraday's experiments have elicited electric currents 
from the liberated magnetism. Magnetism is one of the mani- 
fold forms under which electricity reveals itself. The ancient 
vague presentiment of the identity of electric and magnetic 
attraction has been verified in our own times. " When elec- 
trum (amber)," says Pliny, in the spirit of the Ionic natural 
philosophy of Thales,* "is animated by friction and heat, it 
will attract bark and dry leaves precisely as the loadstone at- 
tracts iron." The same words may be found in the literature 
of an Asiatic nation, and occur in a eulogium on the load- 
stone by the Chinese physicist Kuopho.f I observed with as- 

Mouut Crozier, west-northwest of the south magnetic pole, at a place 
where Captain .Tames Ross tbund the inclination of the needle to be 87° 
11' (Sabine, Contributions to Terrestrial Magnetisyn, 1843, No. 5, p. 
231); the latter, observed by Erman, at 19° 59' S. lat., and 37° 24' W. 
long, from Paris, 320 miles eastward from the Brazilian coast of Espiritu 
Santo (Erman, Phys. Beoh., 1841, s. 570), at a point where the inclina- 
tion is only 7° 55'. The actual ratio of tlie two intensities is therefore 
as 1 to 2-906. It was long believed that the greatest intensity of the 
magnetic force was only two and a half times as great as the weakest 
exhibited on the Earth's surface. (Sabine, Report on Magnetic In- 
tensity, p. 82.) 

* Of amber (succinum, glessum) Pliny observes (xxxvii., 3), " Gen- 
era ejus plura. Attritu digitorum accepta caloris anima trahunt in se 
paleas ac folia arida qute levia sunt, ac ut magnes lapis ferri ramenta 
quoque." (Plato, ira Timceo, p. 80. Martin, Etude snr le Tim^e, t. ii., 
p. 343-346. Strabo, xv., p. 703, Casaub. ; Clemens Alex., Strom., ii., 
p. 370, where, singularly enough, a diffei'ence is made between to 
aovxiov and to rjXsKTpov.) When Tlmles, in Aristot., de Anima, 1, 2, 
and Hippias, in Diog. Laert., i., 24, describe the magnet and amber as 
possessing a soul, they refer only to a moving principle. 

t " The magnet attracts iron as amber does the smallest grain of mus- 
tard seed. It is like a breath of wind which mysteriously penetrates 
through both, and communicates itself with the rapidity of an arrow." 
These are the words of Kuopho, a Chinese panegyrist on the magnet, 
who wrote in the beginning of the fourth century. (Klaproth.Lef^r.? o 
M. A. de Humboldt, snr V Inventio7i de la Boussole, 1834, p. 125. ^ 



MiAGNETISM. 189 

tonishment, on the wojdy banks of the Orinoco, in the sports 
ol" the natives, that the excitement of electricity by friction 
was known to these savage races, who occupy the very lowest 
place in the scale of humanity. Children may be seen to rub 
the dry, flat, and shining seeds or husks of a traihng plant 
(probably a Negretia) until they are able to attract threads 
of cotton and pieces of bamboo cane. That which thus de- 
lights the naked copper-colored Indian is calculated to awaken 
in our minds a deep and earnest impression. What a chasm 
divides the electric pastime of these savages from the discov- 
ery of a metallic conductor discharging its electric shocks, or a 
pile composed of many chemically-decomposing substances, or 
a light-engendering magnetic apparatus I In such a chasm 
lie buried thousands of years that compose the history of the 
intellectual development of mankind I 

The incessant change or oscillatory motion which we dis- 
cover in all magnetic phenomena, whether in those of the in- 
clination, declination, and intensity of these forces, according 
to the hours of the day and the night, and the seasons and the 
course of the whole year, leads us to conjecture the existence 
of very various and partial systems of electric currents on the 
surface of the Earth. Are these currents, as in Seebeck's ex- 
periments, thermo-magnetic, and excited directly from unequal 
distribution of heat ? or should we not rather regard them as 
induced by the position of the Sun and by solar heat ?* Have 
the rotation of the planets, and the different degrees of velocity 
which the individual zones acquire, according to their respect- 
ive distances from the equator, any influence on the distribii 
tion of magnetism ? Must we seek the seat of these currents, 
that is to say, of the disturbed electricity, in the atmosphere, 
in the regions of planetary space, or in the polarity of the Sun 
and Moon ? G^ilileo, in his celebrated Dialogo, was inclined 
to ascribe the parallel direction of the axis of the Earth to a 
magnetic point of attraction seated in universal space. 

If we represent to ourselves the interior of the Earth as 
fused and undergoing an enormous pressure, and at a degree 
of temperature the amount of which we are unable to assign, 

* " The phenomena of periodical variations depend manifestly on the 
action of solar heat, operating probably through the medium of thermo- 
electric currents induced on the Earth's surface. Beyond this rude 
guess, however, nothing is as yet known of their physical cause. It ia 
even still a matter of speculation v^diether the solar influence be a prin- 
cipal or only a subordinate cause in the phenomena of terrestrial mag 
netism." (^Observations to he made in the Antarctic Expedition, 1840. 
p. 35.) 



190 COSMOS. 

we must renounce all idea of a magnetic nucleus of the Earth. 
All magnetism is certainly not lost until we arrive at a white 
heat,* and it is manifested when iron is at a dark red heat , 
however different, therefore, the modifications may be which 
are excited in substances in their molecular state, and in the 
coercive force depending upon that condition in experiments 
of this nature, there will still remain a considerable thickness 
of the terrestrial stratum, which, might be assumed to be the 
seat of magnetic currents. The old explanation of the horary 
variations of declination by the progressive warming of the 
Earth in the apparent revolution of the Sun from east to west 
must be limited to the uppermost surface, since thermometers 
sunk into the Earth, which are now being accurately observed 
at so many different places, show how slowly the solar heat 
penetrates even to the inconsiderable depth of a few feet. 
Moreover, the thermic condition of the surface of water, by 
which two thirds of our planet is covered, is not favorable to 
such modes of explanation, when we have reference to an im- 
mediate action and not to an effect of induction in the aerial 
and aqueous investment of our terrestrial globe. 

In the present condition of our knowledge, it is impossible 
to aflbrd a satisfactory reply to all questions regarding the ulti- 
mate physical causes of these phenomena. It is only with ref- 
erence to that which presents itself in the triple manifestations 
of the terrestrial force, as a measurable relation of space and 
time, and as a stable element in the midst of change, that 
science has recently made such brilliant advances by the aid 
of the determination of mean numerical values. From To- 
ronto in Upper Canada to the Cape of Good Hope and Van Die- 
men's Land, from Paris to Pekin, the Earth has been covered, 
since 1828, with magnetic observatories,t in which every regu- 

* Barlow, in the Philos. Trans, for 1822, Pt. i., p. 117 ; Sir David 
Brewster, Treatise on Magnetism, p. 129. Long before the times of 
Gilbert and Hooka, it was taught in the Chinese work Ow-thsa-tsou 
that heat diminished the directive force of the magnetic needle. (Kla- 
proth, Leitre a M. A. de Humholdl, stir V Invc7itio7i de la Boussole, p. 96.) 

t As the first demand for the establishment of these observatories (a 
net-work of stations, provided with similar instruments) proceeded 
from me, I did not dare to cherish the hope that I should live long 
enough to see the time when both hemispheres should be uniformly 
covered with magnetic houses under the associated activity of able 
physicists and astronomers. This has, however, been accomplished, 
and chiefly through the liberal and continued support of the Russian and 
British governments. 

In the yeai-s 1806 and 1807, 1 and my friend and fellow-laborer, Herr 
Ollmanus, while at Berlin, observed the movements of the needle, espe- 



MAGNETISM. 191 

lar or in'egular manifestation of the terrestrial force is detected' 
by uninterrupted and simultaneous observations, A variation 

daily at the times of the solstices and equinoxes, frona hour to hour, 
and often from half hour to half hour, for five or six days and nights 
uninterruptedly. I had persuaded myself that continuous and uninter- 
rupted observations of several days and nights (observatio perpetua) 
were preferable to the single observations of many months. The ap- 
paratus, a Prony's magnetic telescope, suspended in a glass case by a 
thread devoid of torsion, allowed angles of seven or eight seconds to be 
read off on a finely-divided scale, placed at a proper distance, and 
lighted at night by lamps. Magnetic perturbations (storms), which oc- 
casionally recurred at the same hour on several successive nights, led 
me even then to desire extremely that similar apparatus should be used 
to the east and west of Berlin, in order to distinguish general terres- 
trial phenomena from those which are mere local disturbances, depend- 
ing on the inequality of heat in different parts of the Earth, or on the 
cloudiness of the atmosphere. My departure to Paris, and the long 
period of political distui'bance that involved the whole of the west of 
Europe, prevented my wish from being then accomplished. CErsted's 
great discovery (1820) of the intimate connection between electricity 
and magnetism again excited a general interest (which had long flag- 
ged) in the periodical variations of the electro-magnetic tension of the 
Earth. Arago, who many years previously had commenced in the Ob- 
servatory at Paris, with a new and excellent declination instrument by 
Gambey, the longest uninterrupted series of horaiy observations which 
we possess in Europe, showed, by a comparison with simultaneous ob- 
servations of perturbation made at Kasan, what advantages might be 
obtained from corresponding measurements of declination. When I 
returned to Berlin, after an eighteen years' residence in France, I had 
a small magnetic house erected in the autumn of 1828, not only with 
the view of carrying on the woi-k commenced in 1806, but more with 
the object that simultaneous observations at hours previously determ- 
ined might be made at Berlin, Paris, and Freiburg, at a depth of 35 
fathoms below the surface. The simultaneous occurrence of the per- 
turbations, and the parallelism of the movements for October and De- 
cember, 1829, were then graphically represented. (Pogg., Annalen, 
bd. xix., s. 357, taf. i.-iii.) An expedition into Northern Asia, Under- 
taken in 1829, by command of the Emperor of Russia, soon gave me an 
opportunity of working out my plan on a larger scale. This plan was 
laid before a select committee of one of the Imperial Academies of 
Science, and, under the protection of the Director of the Mining Depart- 
ment, Count von Cancrin, and the excellent superintendence of Pro- 
fessor Kupffer, magnetic stations were appointed over the whole of 
Northern Asia, from Nicolajeff, in the line through Catharinenburg, Bar- 
naul, and Nertschinsk, to Pekin. 

The year 1832 {Gottinger gelckrte Anzeigen, st. 206) is distinguished 
as the gi'eat epoch in which the profound author of a general theory of 
teiTestrial magnetism, Friedrich Gauss, erected apparatus, constructed 
on a new principle, in the Gottingen Observatoiy. The magnetic ob- 
servatory was finished in 1834, and in the same year Gauss distributed 
new instruments, with instructions for their use, in w^hich the celebrated 
physicist, Wilhelm Weber, took extreme interest, over a large portion 
of Germany and Swa^den, and the whole of Italy. {Rrsnltate der Beob. 
des Magnetischcn Verci/is im Jahr 1338, s, 135, and i\)\i^c\n\., Annalen 



192 COSMOS. 

of j^i-Q^th of the magnetic intensity is measured, and, at cer- 
tain epochs, observations are made at intervals of 2i minutes, 
and continued for twenty-four hours consecutively. A great 
Eno-lisli astronomer and physicist has calculated* that the 
mass of observations w^hich are in progress will accumulate in 
the course of three years to 1,958,000. Never before has so 
noble and cheerful a spirit presided over the inquiry into the 
quantitative relations of the laws of the phenomena of nature. 
We are, therefore, justified in hoping that these laws, when 
compared with those which govern the atmosphere and the 
remoter regions of space, may, by degrees, lead us to a more 
intimate acquaintance with the genetic conditions of magnetic 
phenomena. As yet we can only boast of having opened a 
greater- number of paths which may possibly lead to an ex- 
planation of this subject. In the physical science of terres- 

bd. xxxiii., s. 426.) In the magnetic association that was now formed 
with Gottingen for its center, simultaneous observations have been un- 
dertaken four times a^year since 183G, and continued uninterruptedly 
for twenty-four hours. The periods, however, db not coincide with 
those of the equinoxes and solstices, which I had proposed and followed 
out in 1830. Up to this period, Great Britain, in possession of the most 
extensive commerce and the largest navy in the world, had taken no 
part in the movement which since 1828 had begun to yield important 
results for the more fixed ground- work of terrestrial magnetism. I had 
the good fortune, by a public appeal from Berlin, which I sent in April, 
1836, to the Duke of Sussex, at that time President of the Royal So- 
ciety (Lettre de M. de Humboldt a S.A.R. le Due de Sussex, sur les 
moyens propres a perfectionner la connaissance du magnetisme terrestre 
par I'etablissement des stations magnetiques et d'observations corre- 
spondantes), to excite a fiiendly interest in the undertaking which it 
had so long been the chief object of my wish to cany out. In my let- 
ter to the Duke of Sussex 1 urged the establishment of permanent sta- 
tions in Canada, St. Helena, the Cape of Good Hope, the Isle of France, 
Ceylon, and New Holland, which five years previously I had advanced 
as good positions. The Royal Society appointed a joint physical and 
meteorological committee, -which not only proposed to the government 
the establishment of fixed magnetic observatories in both hemispheres, 
but also the equipment of a naval expedition for magnetic observations 
in the Antarctic Seas. It is needless to proclaim the obligations of 
science in this matter to the great activity of Sir John Herschel, Sabine, 
Airy, and Lloyd, as well as tlie pov^^erful support that was afforded by 
the British Association for the Advancement of Science at their meet- 
ing held at Newcastle in 1838. In .Tune, 1839, the Antarctic magnetic 
expedition, under the command of Captain James Clark Ross, was fully 
arranged ; and now, since its successful return, we reap the double 
fruits of highly important geographical discoveries around the south 
pole, and a series of simultaneous observations at eight or ten magnetic 
stations. 

* See the article on Terrestrial Magnetism, in the Quarterly liemeio 
1840, vol. Ixvi., p. 271-312. 



AURORA BOREALIS. 193 

trial magnetism, which must not be confounded with' the 
purely mathematical branch of the study, those persons only 
will obtain perfect satisfaction who, as in the science oi the 
meteorological processes of the atmosphere, conveniently turn 
aside the practical bearing of all phenomena that can not be 
explained according to their own views. 

Terrestrial magnetism, and the electro-dynamic forces com- 
puted by the intellectual Ampere,* stand in simultaneous and 
intimate cormection with the terrestrial or polar light, as well 
as with the internal and external heat of our planet, whose 
nagnetic poles may be considered as the poles of cold.f The 
oold conjecture hazarded one hundred and twenty-eight years 
since by Halley,| that the Aurora Borealis was a magnetic 
phenomenon, has acquired empirical certainty from Faraday's 
brilliant discovery of the evolution of light by magnetic forces. 
The northern light is preceded by premonitory signs. Thus, 
in the morning before the occurrence of the phenomenon, the 
irregular horary course of the magnetic needle generally indi- 
cates a disturbance of the equilibrium in the distribution of 

* Instead of ascribing the internal heat of the Earth to the transition 
of matter from a vapor-like fluid to a solid condition, which accom- 
panies the formation of the planets, Ampere has propounded the idea, 
which I regard as highly improbable, that the Earth's temperature may 
be the consequence of the continuous chemical action of a nucleus of 
the metals of the earths and alkalies on the oxydizing external crust. 
" It can not be doubted," he observes in his masterly VMorie des Pheno- 
menes Electro-dynaviiques, 1826, p. 199, "that electro-magnetic cur- 
rents exist in the interior of the globe, and that tlie&s cun-ents are the 
cause of its temperature. They arise from the action of a central me- 
tallic nucleus, composed of the metals discovered by Sir Humphrey 
Davy, acting on the surrounding oxydized layer." 

t The remai'kable connection between the curvature of the magnetic 
lines and that of my isothermal lines was first detected by Sir David 
Brewster. See the Transactions of the Royal Society of Edinburgh, vol. 
ix., 1821, p. 318, and Treatise on Magnetism, 1837, p. 42, 44, 47, and 
268. This distinguished physicist admits two cold poles (poles of maxi- 
mum cold) in the northern hemisphere, an American one near Cape 
Walker (73° lat., 100° W. long.), and an Asiatic one (73° lat., 80° E. 
long.) ; whence arise, according to him, two hot and two cold merid- 
ians, i. c, meridians of greatest heat and cold. Even in the sixteenth 
century, Acosta {Historia Nattiral de las Indias, 1589, lib. i., cap. 17), 
grounding his opinion on the observations of a very experienced Portu- 
guese pilot, taught that there were four lines without declination. It 
would seem from the controversy of Henry Bond (the author of The 
Longitude Found, 1676) with Beckborrow, that this view in some meas- 
ure influenced Halley in his theory of four magnetic poles. See my 
Examen Critiqiie dc V Hist, de la Oeographie, t. iii., p. 60. 

X Halley, in the Philosophical Transactions, vol. xxix. (for 1714-1716), 
No. 341. 

Vol. T.— r 



194 COSMOS. 

terrestrial inaffiietism.* When this disturbance attains a g^reat 
degree of intensity, the equilibrium of the distribution is re- 
stored by a discharge attended by a development of light 
' Tiie Auroraf itself is, therefore, not to be regarded as an ex 
ternaily manifested cause of this disturbance, but rather as v 
result of telluric activity, manifested on the one side by tht* 
appearance of the light, and on the other by the vibrations of 
the magnetic needle." The splendid appearance of colored 
polar light is the act of discharge, the termination of ^ mag 
netic storm, as in an electrical storm a development of light — 
the flash of lightning — indicates the restoration of the disturb- 
ed equilibrium in the distribution of the electricity. An elec- 
tric storm is generally confined to a small space, beyond thc- 
limits of which the condition of -the atmospheric electricity 
remains michanged. A magnetic storm, on the other hand, 

* [The Aurora Borealis of October 24tii, 1847, Vvbich was one of the 
most brilliant ever known in this country, was preceded by great mag- 
netic disturbance. On the 22d of October the maximum of the west 
declination was 23° 10' ; on the 23d the positiojj of the magnet was 
continually changing, and the extreme west declinations were between 
22° 44' and 23° 37' ; on the night between the 23d and 24th of October, 
the changes of position were very largo and very frequent, the magnet 
at times moving across the field so rapidly that a difficulty was experi- 
enced in following it. During the day of the 24th of October there wa6 
a constant change of position, but after midnight, when the Aurora be- 
i:au perceptibly to decline in brightness, the disturbance entirely ceased. 
The changes of position of the horizontal-force magnet were as large and 
;i8 frequent as those of the declination magnet, but the vertical-force 
m:^iriiet was at no time so much atfected as the other two instruineuto. 
See On the Aurora Borealis, as it was seen on Sutidai/ evening, October 
'lUk, 1847, at Blackheath, by James Glaisher, Esq.. of the Royal Observa- 
tory, Greenwich, iu the London, Edinhirgh, and Dublin Philos. Mag. 
and Journal of Science for Nov., 1847. See further, An Account of the 
Aurora Borealis of October the 'Mth, 1847, by John H. Morgan, Esq. 
We must not omit lo mention that magnetic disturbance is now regis- 
tered by a photographic process : tlie self-registering photographic ap- 
])aratus used for this purpose in the Observatoiy at Greenwich ^yas de- 
signed by Mr. Brooke,.and another ingenious instrument of this kind 
has been invented by Mr. F. Konalds, of the Richmond Observatory.] — 

Tr. 

t Dove, iu Poggend., Annalert,, bd. xx., s. 341 ; bd. xix., s. ;388. 
" The declination needle acts in very nearly the same \A'ay as an atmos- 
pheric electrometer, whose divergence in like manner shows the m- 
ci-eased tension of the electricity before this has become so great as to 
yield a spark." See, also, the excellent observations of Professor Kamtz, 
in his Lehrbvch der Meieorologie, bd. iii., s. ^l\-:Ad, and Sir Dim i! 
Brewster, in his Treatise on Magnetism, p. 280. Regarding the mau- 
iietic properties of the galvanic flame, or luminous arch from a Buii- 
Hen'h carbon and zinc battery, see Casaelmann's Bcobachiungen (Mar- 
bur-. 1844). s. .56-(i2. 



I 

AURORA BOREALIS. l\)^ 

shows its influence on the course of the needle over large por- 
tions of continents, and, as Arago first discovered, far from 
the spot where the evolution of light was visible. It is not 
improbable that, as heavily-charged threatening clouds, owing 
to frequent transitions of the atmospheric electricity to an op 
posite condition, are not always discharged, accompanied b) 
lightning, so likewise magnetic storms may occasion far-ex 
tending disturbances in the horary course of the needle, with 
out there being any positive necessity that the equilibrium of 
the distribution should be restored by explosion, or by the 
passage of luminous effusions from one of the poles to the 
equator, or from pole to pole. 

In collecting all the individual features of the phenomenon 
in one general picture, we must not omit to describe the origin 
and course of a perfectly developed Aurora Borealis. Low 
down in the distant horizon, about the part of the heavens 
which is intersected by the magnetic meridian, the sky which 
was previously clear is at once overcast. A dense wall or 
bank of cloud seems to rise gradually higher and higher, until 
it attains an elevation of 8 or 10 degrees. The color of the 
dark segment passes into brown or violet ; and stars are visi- 
ble through the cloudy stratum, as when a dense smoke dark- 
ens the sky. A broad, brightly-luminous arch, first white, 
then yellow, encircles the dark segment ; but as the brilliant 
arch appears subsequently to the smoky gray segment, we can 
not agree with Argelander in ascribing the latter to the efTect 
of mere contrast with the bright luminous margin.* The 
highest point of the arch of light is, according to accurate ob- 
servations made on this subject,! not generally in the magnet- 
ic meridian itself, but from 5^ to 18^ toward the direction of 
the magnetic declination of the place. $ In northern latitudes, 

* Argelander, in the important observations on the northern light 
embodied in the Vortrdgen gehalten in der physikalisch-okonomischen 
Gessellschaft zu Konigsberg, bd. i., 1834, s. 257-264. 

t For an account of the results of the observations of Lottin, Bravais, 
and Siljerstrom, who spent a winter at Bosekop, on the coast of Lap 
land (70° N. lat.), and in 210 nights saw the northern lights 160 times, 
see the Comvtes Rendus de V Acad, des Sciences, t. x., p. 289, and Mar- 
lins's M6teorologie, 1843, p. 453. See, also, Argelander, in the Vdrtru' 
gen geh. in der Konigsberg Gessellschaft, bd. i., s. 259. 

X [Professor Challis, of Cambridge, states that in the Aurora of Oc- 
tober 24th, 1847, the streamers all converged toward a single point of 
the heavens, situated in or very near a vertical circle passing through 
the magnetic pole. Around this point a corona was formed, the rays 
of which diverged in all directions from the center, leaving a space free 
from light: its azimuth was 18° 41' from soutli to east, and its altitude 
69^ 54'. See Professor Challis, in the Atkenceum, Oct. 31, 1847.]— r>- 



196 COSMOS. 

in the immediate vicinity of the magnetic pole, the smoke-like 
conical segment appears less dark, and sometimes is not even 
seen. Where the horizontal force is the M^eakest, the middle 
of the luminous arch deviates the most from the magnetic 
meridian. 

The luminous arch remains sometimes for hours together 
flashing and kindling in ever- varying undulations,, before rays 
and streamers emanate from it, and shoot up to the zenith. 
The more intense the discharges of the northern light, the 
more bright is the play of colors, through all the varying gra- 
dations from violet and bluish white to green and crimson. 
Even in ordinary electricity excited by friction, the sparks are 
only colored in cases where the explosion is very violent after 
great tension. The magnetic columns of flame rise either 
singly from the luminous arch, blended with black rays simi- 
lar to thick smoke, or simultaneously in many opposite points 
of the horizon, uniting together to form a flickering sea of 
flame, whose brilliant beauty admits of no adequate descrip- 
tion, as the luminous waves are every moment assuming new 
and varying forms. The intensity of this light is at times so 
great, that Lowenorn (on the 29th of June, 1786) recognized 
the coruscation of the polar light in bright sunshine. Motion 
renders the phenomenon more visible. Round the point in 
the vault of heaven which corresponds to the direction of the 
inclination of the needle, the beams unite together to form the 
so-called corona, the crown of the northern light, which en- 
circles the summit of the heavenly canopy with a milder ra- 
diance and unflickering emanations of light. It is only in 
rare instances that a perfect crown or circle is formed, but on 
its completion the phenomenon has invariably reached its 
maximum, and the radiations become less frequent, shorter, 
and more colorless. The crown and the luminous arches 
break up, and the whole vault of heaven becomes covered 
with irregularly-scattered, broad, faint, almost ashy-gray lu- 
minous immovable patches, which in their turn disappear, 
leaving nothing but a trace of the dark, smoke-like segment 
on the horizon. There often remains nothing of the whole 
spectacle but a white, delicate cloud with feathery edges, or 
divided at equal distances into small roundish groups like cir- 
ro-cumuli. 

This connection of the polar light with the most delicate 

(irrous clouds deserves special attention, because it shows that 

he electro-magnetic evolution of light is a part of a meteoro- 

*-> . cal process. Terrestrial n^agnetism here manifests its in- 



AURORA ROREALIS. 197 

fluence on the atmosphere and on the condensation of aqueous 
vapor. The fleecy clouds seen in Iceland by Thienemann, 
and which he considered to be the northern light, have been 
seen in recent times by Franklin and Richardson near the 
American north pole, and by Admiral Wrangel on the Sibe- 
rian coast of the Polar Sea. All remarked " that the Aurora 
flashed forth in the most vivid beams when masses of cirrous 
strata were hovering in the upper regions of the air, and when 
these were so thin that their presence could only be recognized 
by the formation of a halo round the moon." These clouds 
sometimes range themselves, even by day, in a similar manner 
to the beams of the Aurora, and then disturb the course of 
the magnetic needle in the same manner as the latter. On 
the morning after every distinct nocturnal Aurora, the same 
superimposed strata of clouds have still been observed that 
had previously been luminous.* The apparently converging 
polar zones (streaks of clouds in the direction of the magnetic 
meridian), which constantly occupied my attention during my 
journeys on the elevated plateaux of Mexico and in Northern 
Asia, belong probably to the same group of diurnal phenom- 
ena. t 

* John Franklin, Narrative of a Journey to the Shores of the Polar 
Sea, in the Years 1819-1822, p. 552 and 597 ; Thieuemanu, in the 
Edinburgh Philosophical Journal, vol. xx., p. 336 ; Farquharson, in vol. 
vi., p. 392, of the same jouvnal ; Wrangel, Phys. Beob., s. 59. Parry 
even saw the great arch of the northern light continue throughout the 
day. {Journal of a Second Voyage, performed in 1821-1823, p. 156.) 
Something of the same nature was seen in England on the 9th of Sep- 
tember, 1827. A luminous arch, 20^ high, with columns proceeding 
from it, was seen at noon in a part of the sky that had been clear after 
rain. (^Journal of the Royal Institution of Great Britain, 1828, Jan., 
p. 429.) 

t On my return from my American ti'avels, I described the delicate 
cirro-cumulus cloud, which appears uniformly divided, as if by the 
action of I'epuUive forces, under the name of polar bands {bandes ^w- 
laires), because their perspective point of convergence is mostly at first 
in the magnetic pole, so that the parallel rows of fleecy clouds follow 
the magnetic meridian. One peculiarity of this mystei'ious phenomenoL 
is the oscillation, or occasionally the gradually progressive motion, of 
the point of convergence. It is usually observed that the bands are 
only fully developed in one region of the heavens, and they are seeu 
to move first from south to north, and then gradually from east to west. 
I could not trace any connection between the advancing motion of the 
bands and alterations of the currents of air in the higher regions of the 
atmosphere. They occur when tlie air is extremely calm and the 
heavens are quite serene, and are much more common under the 
tropics than in the temperate and frigid zones. I have seen this phe- 
nomenon on the Andes, almost under the equator, at an elevation of 
15.920 feet, and in Northern Asia, \n. the plains of Krasnojarski, south 



198 COSMOS. 

Southern lights have often been seen in England by the in- 
telligent and indefatigable observer Dalton, and northern lights 
have been observed in the southern hemisphere as far as 45^ 
latitude (as on the 14th of January, 1831). On occasions 
that are by no means of rare occurrence, the equilibrium at 
both poles has been simultaneously disturbed. I have discov- 
ered vi'ith certainty that northern polar lights have been seen 
within the tropics in Mexico and Peru. We must distinguish 
between the sphere of simultaneous visibility of the phenom- 
enon and the zones of the Earth where it is seen almost niofht- 
ly. Every observer no doubt sees a separate Aurora of his 
own, as he sees a separate rainbow. A great portion of the 
Earth simultaneously engenders these phenomena of emana- 
tions of light. Many nights may be instanced in which the 
phenomenon has been simultaneously observed in England 
and in Pennsylvania, in Pwome and in Pekin. When it is 
stated that Auroras diminish with the decrease of latitude, 
the latitude must be understood to be magnetic, and as meas- 
ured by its distance from the magnetic pole. In Iceland, in 
Greenland, Newfoundland, on the shores of the Slave Lake, 
and at Fort Enterprise in Northern Canada, these lights ap- 
pear almost every night at certain seasons of the year, cele- 
brating with their flashing beams, according to the mode of 
expression common to the inhabitants of the Shetland Isles, 
" a merry dance in heaven."* While the Aurora is a phe- 
nomenon of rare occurrence in Italy, it is frequently seen in 
the latitude of Philadelphia (39° 57'), owing to the southern 
position of the American magnetic pole. In the districts 
which are remarkable, in the New Continent and the Sibe- 
rian coasts, for the frequent occurrence of this phenomenon, 
there are special regions or zones of longitude in which the 
polar light is particularly bright and brilliant. f The exist- 

of Buchtarmiusk, so similarly developed, that we must regard the in 
fluences producing it as very widely distributed, and as depending on 
general natural forces. See the important observations of Kamtz ( Vor- 
lesungen uber Meteorologie, 1840, s. 146), and the more recent ones of 
Martins and Bravais {Mitiorologie, 1843, p. 117). In south polar bauds, 
composed of veiy delicate clouds, observed by Arago at Paris on the 
23d of June, 1844, dark rays shot upward from an arch running east 
aud west. We have already made mention of black rays, resembling 
dark smoke, as occurring in brilliant nocturnal northern lights. 

* The northern lights are called by the Shetland Islanders " the 
merry dancers." (Kendal, in the Quarterly Journal of Science, new 
series, vol. iv., p. 395.) 

t See Muucke's excellent work in the new edition of Gehler'a Physik 
Wdrterbvcli, bd. vii., i., s. 113-268, and especially s. 158. 



AlKoRA J'.tiKKALlS. 199 

ftnce of local influences can not, theretbre, be denied in theso 
oases. Wrangel saw the brilliancy diminish as he left the 
shores of the Polar Sea, about Nischne-Kolymsk. The ob- 
servations made in the North Polar expedition appear to prove 
that in the immediate vicinity of the magnetic pole the de- 
velopment of light is not in the least degree more intense or 
frequent than at some distance from it. 

The knowledge which we at present possess of the altitude 
of the polar light is based on measurements which, from their 
nature, the constant oscillation of the phenomenon of light, 
and the consequent uncertainty of the angle of parallax, are 
not deserving of much confidence. The results obtained, set- 
ting aside the older data, fluctuate between several miles and 
an elevation of 3000 or 4000 feet; and, -in all probability, 
the northern lights at different times occur at very different 
elevations.* The most recent observers are disposed to place 
the phenomenon in the region of clouds, and not on the con- 
fines of the atmosphere ; and they even believe that the rays 
of the Aurora may be affected by winds and currents of air, if 
the phenomenon of light, by which alone the existence of an 
electro-magnetic current is appreciable, be actually connected 
v/ith material groups of vesicles of vapor in motion, or, more 
correctly speaking, if light penetrate them, passing from one 
vesicle to another. Franklin saw near Great Bear Lake a 
beaming northern light, the lower side of which he thought 
illuminated a stratum of clouds, wliile, at a distance of only 
eighteen geographical miles, Kendal, who was on watch 
throughout the whole night, and never lost sight of the sky, 
perceived no phenomenon of Hght. The assertion, so fre- 
quently maintained of late, that the rays of the Aurora have 
been seen to shoot down to the ground between the spectator 
and some neighboring hill, is open to the charge of optical 
delusion, as ia the cases of strokes of lightning or of the fall 
of fire-balls. 

Whether the magnetic storms, v/hose local character we 
have illustrated by such remarkable examples, share noise as 
well as light in common with electric storms, is a question 

* Farquharsou ia the Edinburgh Philos. Jonrjial, vol. xvi., p. 304 ; 
PUlos. Transact, for 1829, p. 113. 

[Tlie height of the bow of light of the Aurora seen at the Canibridgo 
Observatory, March 19, 1847, was determined by Professors Challis, of 
Cambridge, and Chevallier, of Durham, to be 177 miles above the sur- 
fcice of the Earth. .See tiie notice of this meteor in An Account, of ih-^ 
Aurora Borealis of Oct. 24, 1817, bv Jolin H. Morgan, Esq., isfs.!— 
Tr. 



200 COSMOS. 

that has become difficult to answer, since impHcit confidenco 
is no longer yielded to the relations of Greenland whale-fish- 
ers and Siberian fox-hunters. Northern lights appear to have 
become less noisy since their occurrences have been more ac- 
curately recorded. Parry, Franklin, and Richardson, near 
the north polo ; Thienemann in Iceland ; Gieseke in Green- 
land ; Lottn. and Bravais, near the North Cape ; Wrangel 
and Anjou, on the coast of the Polar Sea, have together seen 
the Aurora thousands of times, but never heard any sound 
attending the phenomenon. If this negative testimony should 
not be deemed equivalent to the positive counter-evidence of 
Hearne on the mouth of the Copper River and of Henderson 
in Iceland, it must be remembered that, although Hood heard 
a noise as of quickly-moved musket-balls and a slight crack- 
ing sound during an Aurora, he also noticed the same noise 
on the following day, when there was no northern light to be 
seen ; and it must not be forgotten that Wrangel and Gieseke 
were fully convinced that the sound they had heard was to 
be ascribed to the contraction of the ice and the crust of the 
snow on the sudden cooling of the atmosphere. The belief 
in a crackling sound has arisen, not among the people gener- 
ally, but rather among learned travelers, because in earlier 
times the northern light was declared to be an efiect of atmos- 
pheric electricity, on account of the luminous manifestation 
of the electricity in rarefied space, and the observers found it 
easy to hear what they wished to hear. Recent experiments 
with very sensitive electrometers have hitherto, contrary to 
the expectation generally entertained, yielded only negative 
results. The condition of the electricity in the atmosphere.* 

* [Mr. James Glaisher, of tlie Royal Observatory, Greenwich, iii his 
interesting Remarks on the Weather d7iring the Quarter ending' Decem- 
ber 31st, 1847, says, " It is a fact well worthy of notice, that from the 
beginning of this quarter till the 20th of December, the electricity of 
the atmosphere was almost always iu a neutral state, so that no signs of 
electi'icity were shown for several days together by any of the electric- 
al instruments." During this period there were eight exhibitions of 
the Aurora Borealis, of which one was the peculiarly bright display of 
the meteor on the 24th of October. These frequent exhibitions of brill- 
iant Aurone seem to depend upon many remarkable meteorological re- 
lations, for we find, according to Mr. Glaisher's statement in the paper 
to which we have already alluded, that the previous fifty years afFoi'd 
nc parallel season to the closing one of 1847. The mean temperature 
of evaporation and of the dew point, the mean elastic force of vapor, 
the mean reading of the barometer, and the mean daily range of the 
readings of the thermometers iu air, were all greater at Greenwich 
during that season of 1847 than the average range of many pi'ececliiig 
years.] — Tr. 



AURORA BOREALIS.. 201 

is not found to be changed during the most intense Aurora ; 
but, on the other hand, the three expressions of the poAver of 
terrestrial magnetism, decHnation, inchnation, and intensity, 
are all affected by polar light, so that in the same night, and 
at different periods of the magnetic development, the same 
end of the needle is both attracted and repelled. The asser 
tion made by Parry, on the strength of the data yielded by 
his observations in the neighborhood of the magnetic pole at 
Melville Island, that the Aurora did not disturb, but rathei 
exercised a calming influence on the magnetic needle, has been 
satisfactorily refuted by Parry's own more exact researches,* 
detailed in his journal, and by the admirable observations of 
Richardson, Hood, and Franklin in Northern Canada, and 
lastly by Bravais and Lottin in Lapland. The process of the 
Aurora is, as has already been observed, the restoration of a 
disturbed condition of equilibrium. The effect on the needle 
is different according to the degree of intensity of the explo- 
sion. It was only unappreciable at the gloomy winter station 
of Bosekop when the phenomenon of Hght was very faint and 
low in the horizon. The shooting cylinders of rays have been 
aptly compared to the flame which rises in the closed circuit 
of a voltaic pile between two points of carbon at a considera- 
ble distance apart, or, according to Fizeau, to the flame rising 
between a silver and a carbon point, and attracted or repelled 
by the magnet. This analogy certainly sets aside the neces- 
sity of assuming the existence of metallic vapors in the atmos- 
phere, which some celebrated physicists have regarded as the 
substratum of the northern light. 

When we apply the indefinite term polar light to the lumin- 
ous phenomenon which we ascribe to a galvanic current, that 
is to say, to the motion of electricity in a closed circuit, we 
merely indicate the local direction in which the evolution of 
light is most freqilently, although by no means invariably, 
seen. This phenomenon derives the greater part of its im- 
portance from the fact that the Earth becomes self-luminous, 
and that as a planet, besides the light which it receives from 
the central body, the Sun, it shows itself capable in itself of 
developing light. The intensity of the terrestrial light, or, 
rather, the luminosity which is diffused, exceeds, in cases of 
the brightest colored radiation toward the zenith, the light 
of the Moon in its first quarter. Occasionally, as on the 7th 
of January, 1831, printed characters could be read without 
difficulty. This almost uninterrupted development of light 

* Kamtz, Lehrbuch der Metecrologie, bd. iii., s. 498 und 501. 

I 2 



202 COSMOS. 

in the Earth leads us by analogy to the remarkable process 
exhibited in Venus. The portion of this planet which is not 
illumined by the Sun often shines with a phosphorescent light 
of its own. It is not improbable that the Moon, Jupiter, and 
the comets shine with an independent light, besides the re- 
flected solar light visible through the polariscope. Without 
speaking of the problematical but yet ordinary mode in which 
the sky is illuminated, when a low cloud may be seen to shine 
with an uninterrupted flickering light for many minutes to- 
gether, we still meet with other instances of terrestrial develop- 
ment of light in our atmosphere. In this category we may 
reckon the celebrated luminous mists seen in 1783 and 1831 ; 
the steady luminous appearance exhibited without any flick- 
ering in great clouds observed by Rozier and Beccaria ; and 
lastly, as Arago* well remarks, the faint difliised light which 
guides the steps of the traveler in cloudy, starless, and moon- 
less nights in autumn and winter, even when there is no snow 
on the ground. As in polar light or the electro-magnetic 
storm, a current of brilliant and often colored light streams 
through the atmosphere in high latitudes, so also in the torrid 
zones between the tropics, the ocean simultaneously develops 
light over a space of many thousand square miles. Here the 
magical effect of light is owing to the forces of organic nature. 
Foaming with light, the eddying waves flash in phosphores- 
cent sparks over the wide expanse of waters, where every scin- 
tillation is the vital manifestation of an invisible animal world. 
So varied are the sources of terrestrial light I Must we still 
suppose this light to be latent, and combined in vapors, in 
order to explain Mose/s images 2^Toduced at a distance — a 
discovery in which reality has hitherto manifested itself like 
a mere phantom of the imagination. 

As the internal heat of our planet is connected on the one 
hand with the generation of electro-magrietic currents and 
the process of terrestrial light (a consequence of the magnetic 
storm), it, on the other hand, discloses to us the chief source 
of geognostic phenomena. We shall consider these in their 
connection with and their transition from merely dynamic dis- 
turbances, from the elevation of whole continents and mount- 
ain chains to the development and effusion of gaseous and 

* Arago, on the dry fogs of 1783 and 1831, which illuminated the 
night, in the Annuairedu Bureau des Longitudes, 1832, p. 246 and 250; 
and, regarding extraordinary lumiuoas appearances in clouds without 
storms, see Notices sur la Tonnerre. in the Annuaire pour Van. 1838. 
p. 279-285. 



GK!)(;i\(»STI(' I'llKVOMKXA. 203 

liquid tiuids, of hot mud, aud of those heated and molten 
earths which become sohdified into crystalline mineral masses. 
Modern geognosy, the mineral portion of terrestrial physics, 
has made no slio;ht advance in having investisfated this con 
nection of phenomena. This investigation has led us away 
from the delusive hypothesis, by which it was customary for- 
merly to endeavor to explain, individually, every expression of 
force in the terrestrial globe : it shows us the connection of 
the occurrence of heterogeneous substances with that which 
only appertains to changes in space (disturbances or eleva- 
tions), and groups together phenomena which at first sight 
appeared most heterogeneous, as thermal springs, eilusion of 
carbonic acid and sulphurous vapor, innocuous salses (mud 
eruptions), and the dreadful devastations of volcanic mount- 
ains.* In a general view of nature, all these phenomena are 
fused together in one sole idea of the reaction of the interior 
of a planet on its external surface. We thus recognize in the 
depths of the earth, and in the increase of temperature with 
the increase of depth from the surface, not only the germ of 
disturbing movements, but also of the gradual elevation of 
whole continents (as mountain chains on long fissures), of vol- 
canic eruptions, and of the manifold production of mountains 
and mineral masses. The influence of this reaction ot" the 
interior on the exterior is not, however, limited to inorganic 
nature alone. It is highly probable that, in an earlier world, 
more powerful emanations of carbonic acid gas, blended with 
the atmosphere, must have increased the assimilation of car- 
bon in vegetables, and that an inexhaustible supply of com- 
bustible matter (lignites and carboniferous formations) must 
have been thus buried in the upper strata of the earth by the 
revolutions attending the destruction of vast tracts of forest. 
We likewise perceive that the destiny of mankind is in part 
dependent on the formation of the external surface of the earth, 
the dfi-ection of mountain tracts and high lands, and on the 
distribution of elevated continents. It is thus granted to the 
inquiring mind to pass from link to link along the chain of 
phenomena until it reaches the period when, in the solidifying 
process of our planet, and in its first transition from the gas- 
eous form to the agglomeration of matter, that portion of the 
inner heat of the Earth w^as developed, which does not belong 
to the action of the Sun. 

* [See Manteirs Wonders of Geology, 1848, vol. i., p. .34, 3(j, 10.5; 
also Lyell's Principcs of Geology, vol. ii., and Daubeney On Volcanoes, 
^d ed., 1848. Part ii.. cli. xxxii., xxxiii.] — 2r. 



204 coor.TOS. 

Tn order to give a general delineation of the causal con- 
nection of geognostical phenomena, we will begin with those 
whose chief characteristic is dynamic, consisting in motion 
and in change in space. Earthquakes manifest themselves 
by quick and successive vertical, or horizontal, or rotatory vi- 
brations.* In the very considerable number of earthquakes 
which I have experienced in both hemispheres, alike on land 
and at sea, the two first-named kinds of motion have often ap- 
peared to me to occur simultaneously. The mine-like explo- 
sion — the vertical action from below upward — was most strik- 
ingly manifested in the overthrow of the town of Riobamba 
in 1797, when tlie bodies of many of the inhabitants were 
found to have been hurled to Cullca, a hill several hundred 
feet in 'height, and on the opposite side of the River Lican. 
The propagation is most generally effected by undulations in 
a linear direction,! with a velocity of from twenty to twenty- 
eight miles in a minute, but partly in circles of commotion or 
large ellipses, in which the vibrations are propagated with 
decreasing intensity from a center toward the circumference. 
There are districts exposed to the action of two intersecting 
circles of commotion. In Northern Asia, where the Father 
of History, t and subsequently Theophylactus Simocatta,§ de- 
scribed the districts of Scythia as free from earthquakes, I 
have observed the metalliferous portion of the Altai Mount- 
ains under the influence of a two-fold focus of commotion, the 
Lake of Baikal, and the volcano of the Celestial Mountain 
(Thianschan).ll When the circles of commotion intersect one 
another — when, for instance, an elevated plain lies between 
two volcanoes simultaneously in a state of eruption, several 
wave-systems may exist together, as in fluids, and not mu- 
tually disturb one another. We may even suppose interfer- 

* [See Daubeney On Volcanoes, 2d ed., 1848, p. 509.]— Tr. 
t [Ou the linear direction of earthquakes, see Daubeney Oit^Volca- 
noes, p. 515.] — Tr. 

I Herod, iv., 28. The prostration of the colossal statue of Memnou, 
which has been again restored (Leti'onne, La Statue Vocale de Memnon, 
1835, p. 25, 26), presents a fact in opposition to the ancient prejudice 
that Egypt is free from earthquakes (Pliny, ii., 80); but the valley of 
the Nile does lie external to the circle of commotion of Byzantium, the 
Archipelago, and Syria (Ideler ad Aristot., Meteor., p. 584). 

§ Saint-Martin, in the learned notes to Lebeau, Hist, du Bas Empire, 
t. Ix., p. 401. 

II Humboldt, Asie Centrale, t. ii., p. 110-118. In regard to the dif- 
ference between agitation of the surface and of the strata lying beneath 
it, see Gay-Lussac, in the Annates de Chimie et de Physique, t. xxii., p 
499. 



I EARTHaUAKES. 205 

ence to exist here, as in the intersecting waves of sound. The 
extent of the propagated waves of commotion will be increased 
on the upper surface of the earth, according to the general law 
of mechanics, by which, on the transmission of motion in elas- 
tic bodies, the stratum lying free on the one side endeavors to 
separate itself from the other strata. 

Waves of commotion have been investigated by means of 
the pendulum and the seismometer* with tolerable accuracy in 
respect to their direction and total intensity, but by no means 
with reference to the internal nature of their alternations and 
their periodic intumescence. In the city of Quito, which lies 
at the foot of a still active volcano (the Rucu Pichincha), 
and at an elevation of 9540 feet above the level of the sea, 
which has beautiful cupolas, high vaulted churches, and mass- 
ive edifices of several stories, I have often been astonished 
that the violence of the nocturnal earthquakes so seldom 
causes fissures in the walls, while in the Peruvian plains os- 
cillations apparently much less intense injure low reed cot- 
tages. The natives, who have experienced many hundred" 
earthquakes, believe that the difference depends less upon the 
length or shortness of the waves, and the slowness or rapidity 
of the horizontal vibrations,! than on the uniformity of the 
motion in opposite directions. The circling rotatory commo- 
tions are the most uncommon, but, at the same time, the most 
dangerous. Walls were observed to be twisted, but not thrown 
down ; rows of trees turned from their previous parallel direc- 

* [This iustrument, iu its simplest form, cousists merely of a basin 
filled with some viscid liquid, which, on the occurrence of a shock of 
an earthquake of sufficient force to disturb the equilibrium of the 
building iu which it is placed, is tilted on one side, and the liquid made 
to rise in the same direction, thus showing by its height the degree of 
the disturbance. Professor J. Forbes has invented an instrument of 
this nature, although on a greatly improved plan. It consists of a vert- 
ical metal rod, having a ball of lead movable upon it. It is supported 
upon a cylindrical steel wire, which may be compressed at pleasure by 
means of a screw. A lateral movement, such as that of an earthquake, 
which carries forward the base of the instrument, can only act upon the 
ball through the medium of the elasticity of the wire, and the direction 
of the displacement will be indicated by the plane of vibration of the 

Eeudulum. A self-registering apparatus is attached to the machine, 
ee Professor J. Forbes's account of his invention in Edinb. Phil. Trans., 
vol. XV., Part i.] — Tr. 

t " Tutissimum est cum vibrat crispante aedificiorum crepitu ; et cum 
hitumescit assurgens alternoque motu residet, iunoxium et cum concur- 
rentia tecta contrario ictu arietant; quoniam alter motus alteri renititur. 
Undantis inclinatio et fluctus more quaidam volutatio infesta est, aut cum 
in unara partem totus se motus impellit." — Plin., ii., 8*2. 



206 coSxMos. 

tion ; and fields covered with different kinds of plants found 
to be displaced in the great earthquake of Riobamba, in the 
province of Quito, on the 4th of February, 1797, and in that 
of Calabria, between the 5th of February and the 28th of 
March, 1783 The phenomenon of the inversion or displace- 
ment of fields and pieces of land, by which one is made to oc- 
cupy the place of another, is connected with a translatory mo- 
tion or penetration of separate terrestrial strata. When I 
made the plan of the ruined town of Riobamba, one particu- 
lar spot was pointed out to me, where all the furniture of one 
house had been found under the ruins of another. The loose 
earth had evidently moved like a fluid in currents, which must 
be assumed to have been directed first downward, then hori- 
zontally, and lastly upward. It was found necessary to ap- 
peal to the Audie7icia, or Council of Justice, to decide upon 
the contentions that arose regarding the proprietorship of ob- 
jects that had been removed to a distance of many hundred 
toises. 

In countries where earthquakes are comparatively of much 
less frequent occurrence (as, for instance, in Southern Europe), 
a very general belief prevails, although unsupported by the 
authority of inductive reasoning,* that a calm, an oppressive 

* Even in Italy they have begun to observe that earthquakes are un- 
connected with the state of the weather, that is to say, with the appear- 
ance of the heavens immediately before the shock. The numerical re- 
sults of Friedrich Hoffmann {Hinterlassene Werke, bd. ii., 366-375) ex- 
actly correspond with the experience of the Abbate Sciua of Palermo. 
I have myself several times observed I'eddish clouds on the day of an 
earthquake, and shortly before it; on the 4th of November, 1799, I ex- 
perienced two sharp shocks at the moment of a loud clap of thunder. 
{Relat. Hist., liv. iv., chap. 10.) The Turin physicist, Vassalli Eandi, 
observed Volta's electrometer to be strongly agitated during the pro- 
tracted earthquake oT Pignerol, which lasted from the 2(1 of April to 
the 17th of May, 1808; Journal de Physique, t. Ixvii., p. 291. But 
these indications presented by clouds, by modifications of atmospheric 
electricity, or by calms, can not be regarded as generally or necessarily 
connected with earthquakes, since in Quito, Peru, and Chili, as well 
as in Canada and Italy, many earthquakes are observed along with tlie 
purest and clearest skies, and with the freshest land and sea breezes. 
But if no meteorological phenomenon indicates the coming earthqunke 
either on the morning of the shock or a few dnys previously, the iuflii- 
ence of certain periods of the year (the vernal and autumnal equinoxes), 
the commencement of the rainy season in the tropics after long drought. 
and the change of the monsoons (according to general belief), can not 
6e overlooked, even though the genetic connection of meteorological 
processes with those going on in the interior of our globe is still envel- 
oped in obscurity. Numerical inquiries on the distribution of earth- 
quakes throughout the course of the year, such as tho.se of Von Hoff, 
Peter Merian, and Filedrich Hoffmann, bear testimony to their frequency 



EARTHQUAKErJ. 207 

leat, and a misty horizon, are always the forerunners of this 
phenomenon. The fallacy of this popular opinion is not only 
refuted by my own experience, but likewise by the observations 
of all those who have lived many years in districts where, as 
in Cumana, Quito, Peru, and Chili, the earth is frequently 
and violently agitated. I have ielt earthquakes in clear air 
and a fresh east wind, as well as in rain and thunder storms. 
The regularity of the horary changes in the declination of the 
magnetic needle and in the atmospheric pressure remained un 
disturbed between the tropics on the days when earthquakes 
occurred.* These facts agree with the observations made bj' 
Adolph Erman (in the temperate zone, on the 8th of March, 
1829) on the occasion of an earthquake at Irkutsk, near the 
Lake of Baikal. During the violent earthquake of Cumana, 
on the 4th of November, 1799, I found the declination and 
the intensity of the magnetic force alike unchanged, but, to 
my surprise, the inclination of the needle was diminished about 
48 '.t There was no ground to suspect an error in the calcu- 
lation, and yet, in. the many other earthquakes which I have 
experienced on the elevated plateaux of Quito and Lima, the 
inclination as well as the other elements of terrestrial mag- 
netism remained always unchanged. Although, in general, 
the processes at work within the interior of the earth may not 
be announced by any meteorological phenomena or any special 
appearance of the sky, it is, on the contrary, not improbable, 
as we shall soon see, that in cases of violent earthquakes some 
eSect may be imparted to the atmosphere, in consequence of 
which they can not always act in a purely dynamic manner. 

at the periods of the equiuoxes. It is singular that Pliny, at the end of 
his fanciful theory of earthquakes, names the entire frightful phenom- 
enon a subterranean stoi'm ; not so much in consequence of the rolling 
sound which frequently accompanies the shock, as because the elastic 
forces, concussive by their tension, accumulate in the interior of the 
earth when they are absent in the atmosphere ! " Ventos in causa esse 
non dubium reor. Neque enim unquara intremiscunt terrae, nisi sopito 
mari, coeloque adeo tranquillo, ut volatus avium non pendeant, subtracto 
omni spiritu qui vehit; nee unquam nisi post ventos conditos, scilicet 
in venas et cavernas ejus occulto afflatu. Neque aliud est in terra 
tremor, quam in nube tonitruum ; nee hiatus aliud quam cum fulmen 
erumpit, incluso spiritu luctante et ad libertatem exire nitente." (Plin., 
ii., 79.) The germs of almost every thing that has been observed or 
imagined on the causes of earthquakes, up to the present day, may be 
found in Seneca, Nat. Qucest.. vi., 4-31. 

* I have given proof that the course of the horaiy variations of the 
Darometer is not affected before or after earthquakes, in my Relat. Hist.. 
t. i., p. 311 and 513. 

t Humboldt, Relat. Hist., t. i.. p. 51.5-517. 



208 COSMOS. 

• 

During- the long-continued trembling of the ground in the 
Piedmontese valleys of Pelis and Clusson, the greatest changes 
in the electric tension of the atmosphere were observed while 
the sky was cloudless. The intensity of the hollow noise which 
generally accompanies an earthquake does not increase in the 
same degree as the force of the oscillations. I have ascertain- 
ed with certainty that the great shock of the earthquake of 
Riobamba (4th Feb., 1797) — one of the most fearful phenom- 
ena recorded in the physical history of our planet — was not 
accompanied by any noise whatever. The tremendous noise 
{el gran ruido) which was heard below the soil of the cities 
of Quito and Ibarra, but not at Tacunga and Hambato, near- 
er the center of the motion, occurred between eighteen and 
twenty minutes after the actual catastrophe. In the cele- 
brated earthquake of Lima and Callao (28th of October, 
1746), a noise resembling a subterranean thunder-clap was 
heard at Truxillo a quarter of an hour after the shock, and 
unaccompanied by any trembling of the ground. In like 
manner, long after the great earthquake in New Granada, on 
the 16th of November, 1827, described by Boussingault, sub- 
terranean detonations were heard in the whole valley of Cauca 
during twenty or thirty seconds, unattended by motion. The 
nature of the noise varies also very much, being either rolling, 
or rustling, or clanking like chains when moved, or like near 
thunder, as, for instance, in the city of Quito ; or, lastly, clear 
and ringing, as if obsidian or some other vitrified masses were 
struck in subterranean cavities. As solid bodies are excellent 
conductors of sound, which is propagated in burned clay, for 
instance, ten or twelve times quicker than in the air, the sub- 
terranean noise may be heard at a great distance from the 
place where it has originated. In Caraccas, in the grassy 
plains of Calabozo, and on the banks of the Rio Apure, which 
falls into the Orinoco, a tremendously loud noise, resembling 
thunder, was heard, unaccompanied by an earthquake, over 
a district of land 9200 square miles in extent, on the 30th of 
April, 1812, while at a distance of 632 miles to the north- 
east, the volcano of St. Vincent, in the small Antilles, poured 
forth a copious stream of lava. With respect to distance, this 
was as if an eruption of Vesuvius had been heard in the north 
of France. In the year 1744, on the great eruption of the 
volcano of Cotopaxi, subterranean noises, resembling the dis- 
charge oi' cannon, were heard in Honda, on the Magdalena 
River. The crater of Cotopaxi lies not only 18,000 feet high- 
er than. Honda, but these two points are separated by the co- 



« EARTHaUAKES. 209 

iossal mountain chain of Quito, Pasto, and Popayan, no less 
than by numerous valleys and clefts, and they are 436 miles 
apart. The sound was certainly not propagated through the 
air, but through the earth, and at a great depth. During the 
violent earthquake of New Granada, in February, 1835, sub- 
terranean thunder was heard simultaneously at Popayan, Bo- 
gota, Santa Marta, and Caraccas (where it continued for seven 
hours without any movement of the ground), in Haiti, Jamai 
ca, and on the Lake of Nicaragua. 

These phenomena of sound, when unattended by any per- 
ceptible shocks, produce a peculiarly deep impression even on 
persons who have lived in countries where the earth has been 
frequently exposed to shocks. A striking and unparalleled in- 
stance of uninterrupted subterranean noise, unaccompanied by 
any trace of an earthquake, is the phenomenon known in the 
Mexican elevated plateaux by the name of the "roaring and 
the subterranean thunder" [bramidos y truenos subterraneos) 
of Guanaxuato.* This celebrated and rich mountain city 
lies far removed from any active volcano. The noise began 
about midnight on the 9th of January, 1784, and continued 
for a month. I have been enabled to give a circumstantial 



* On the bramidos of Guanaxuato, see my Essai Polit. sur la Noiiv. 
Espagne, t. i., p. 303. The subterranean noise, unaccompanied with 
any appreciable shock, in the deep mines and on the surface (the town 
of Guanaxuato lies G830 feet above the level of the sea), was not heard 
in the neighboi'ing elevated plains, but only in the mountainous parts 
of tile Sierra, from the Cuesta de los Aguilares, ueai' Marfil, to the north 
of Santa Rosa. There were individual parts of the Sierra 24-28 miles 
northwest of Guanaxuato, to the other side of Chichi mequillo, near the 
boiling spring of San Jose de Comangillas, to which the waves of sound 
did not extend. Extremely stringent measures were adopted by the 
magistrates of the large mountain towns on the 14th of January, 1784, 
when the terror produced by these subterranean thunders was at its 
height. " The flight of a wealthy family shall be punished with a fine 
of 1000 piasters, and that of a poor family with two months' imprison- 
ment. The militia shall bring back the fugitives." One of the most 
remarkable points about the whole affair is the opinion which the mag- 
istrates (el cabildo) cherished of their own superior knowledge. In 
one of their proclavias, I find the expression, " The magistrates, in their 
wisdom (en su sabiduria), will at once know when there is actual dan- 
ger, and will give orders for flight ; for the present, let processions be 
instituted." The terror excited by the tremor gave x'ise to a famine, 
since it prevented the importation of com from the table-lands, where 
it abounded. The ancients were also aware that noises sometimes ex- 
isted without earthquakes. — Aristot., Meteor., W., p. 802; Plin., ii., 80. 
Thf; singular noise that was heard from March, 1822, to September, 
1824, in the Dalmatian island Meleda (sixteen miles from Ragusa), and 
on which Partsch has thrown much light, was occasionally accompanied 
by shocks. 



210 COSMOS. 

description of it from the report of many witnesses, and from 
the documents of the municipahty, of which I was allowed to 
make use. From the 13th to the IGth of January, it seemed 
to the inhabitants as if heavy clouds lay beneath their feet, 
from which issued alternate slow rolling sounds and short, 
quick claps of thunder. The noise abated as gradually as it 
had begun. It was limited to a small space, and was not 
heard in a l)asaltic district at the distance of a few miles. 
Almost all the inhabitants, in terror, left the city, in which 
large masses of silver ingots were stored ; but the most cour- 
ageous, and those more accustomed to subterranean thunder, 
soon returned, in order to drive oft^ the bands of robbers who 
had attempted to possess themselves of the treasures of the 
city. Neither on the surface of the earth, nor in mines 1600 
feet in depth, was the slightest shock to be perceived. No 
similar noise had ever before been heard on the elevated table- 
land of Mexico, nor has this terrific phenomenon since occurred 
there. Thus clefts are opened or closed in the interior of the 
earth, by which waves of sound penetrate to us or are impeded 
in their propagation. 

The activity of an igneous mountain, however terrific and 
picturesque the spectacle may be which it presents to our con- 
templation, is ahvays limited to a very small space. It is far 
otherwise with earthquakes, which, although scarcely per- 
ceptible to the eye, nevertheless simultaneously propagate their 
waves to a distance of many thousand miles. The great 
earthquake Vvdiich destroyed the city of Lisbon on the 1st of 
November, 1755, and whose effects were so admirably investi- 
gated by the distinguished philosopher Emmanuel Kant, was 
felt in the Alps, on the coast of Sweden, in the Antilles, An- 
tigua, Barbadoes, and Martinique ; in the great Canadian 
Lakes, in Thuringia, in the fiat country of Northern Ger- 
many, and in the small inland lakes on the shores of the Bal- 
tic."^ Remote springs were interrupted in their flow, a phe- 
nomenon attending earthquakes which had been noticed among 
the ancients by Demetrius the Callatian. The hot springs of 
Toplitz dried up, and returned, inundating every thing around, 
and having their waters colored with iron ocher. In Cadiz 

* [It has been computed that the shock of this earthquake pervaded 
an area of 700,000 miles, or the twelfth part of the circumference of the 
globe. This dreadful shock lasted only five minutes: it happened about 
nine o'clock in the morning of the Feast of All Saints, when almost the 
whole population was within the churches, owing to which circum- 
stance no less than 30,000 persons perished by the fall of these edifices. 
See Daubeney 0« Volcanoes, p. .514-517.] — Tr 



EARTHaLTAKEf;. 2H 

die sea rose to an elevation of sixty-four feet, while in the An- 
tilles, where the tide usually rises only from twenty-six to 
twenty-eight inches, it suddenly rose above twenty teet, the 
water being of an inky blackness. It has been computed that 
on the 1st of November, 1755, a portion of the Earth's sur- 
face, four times greater than that of Europe, was simultane- 
ously shaken. As yet there is no manifestation offeree known 
to us, includino- even the murderous inventions of our own 
race, by which a greater number of people have been killed in 
the short space of a few minutes : sixty thousand were de- 
stroyed in Sicily in 1693, from thirty to forty thousand in the 
earthquake of Riobamba m 1797, and probably five times as 
many in Asia Minor and Syria, under Tiberius and Justinian 
the elder, about the years 19 and 526. 

There are instances in which the earth has been shaken for 
many successive days in the chain of the Andes in South 
America, but I am only acquainted with the following cases 
in which shocks that have been felt almost every hour for 
months together have occurred far from any volcano, as, for 
instance, on the eastern declivity of the Alpine chain of Mount 
Cenis, at Fenestrelles and Pignerol, from April, 1808 ; be- 
tween New ]Madrid and Little Prairie, ^^ north of Cincinnati, 
in the United States of America, in December, 1811, as well 
as through the whole winter of 1812 ; and in the Pachalik of 
Aleppo, in the months of August and September, 1822. As 
the mass of the people are seldom able to rise to general views, 
and are consequently always disposed to ascribe great phe- 
nomena to local telluric and atmospheric processes, wherever 
the shaking of the earth is continued for a long time, fears of 
the eruption of a new volcano arc awakened. In some few 
cases, this apprehension has certainly proved to be well ground- 
ed, as, for instance, in the sudden elevation of volcanic islands, 
and as we see in the elevation of the volcano of Jorullo, a 
mountain elevated 1684 feet above the ancient level of the 
neighboring plain, on the 29th of September, 1759, after mnety 
days of earthquake and subterranean thunder. 

If we could obtain information regarding the daily condi- 
tion of all the earth's surface, we should probably discover that 
the earth is almost always undergoing shocks at some point 
of its superficies, and is continually influenced by the reaction 

* Drake, Nat. and Statist. View of Cincinnati, p. 232-238: Mitchell, 
m the Transactions of the Lit. and Pliilos. Soc. of New York, vol. i., p. 
281-308. In llie Piedmontese county of Pignerol, glasses of water, fiUod 
to thp vei-\' biini, exhibited for hours a co!ilinuou.s motion. 



212 COSMOS. 

of the interior on the exterior. The frequency and general 
prevalence of a phenomenon which is probably dependent on 
the raised temperature of the deepest molten strata explain 
its independence of the nature of the mineral masses in which 
it manifests itself. Earthquakes have even been felt in the 
loose alluvial strata of Holland, as in the neighborhood of Mid- 
dleburg and Vliessingen on the 23d of February, 1828. Gran- 
ite and mica slate are shaken as well as limestone and sand- 
stone, or as trachyte and amygdaloid. It is not, therefore, the 
chemical nature of the constituents, but rather the mechanical 
structure of the rocks, which modifies the propagation of the 
motion, the wave of commotion. Where this wave proceeds 
along a coast, or at the foot and in the direction of a mountain 
chain, interruptions at certain points have sometimes been re- 
marked, which manifested themselves during the course of 
many centuries. The undulation advances in the depths be- 
low, but is never felt at the same points on the surface. The 
Peruvians^* say of these unmoved upper strata that " they 
form a bridge." As the mountain chains appear to be raised 
on fissures, the walls of the cavities may perhaps favor the di- 
rection of undulations parallel to them ; occasionally, however, 
the waves of commotion intersect several chains almost per 
pendicularly. Thus we see them simultaneously breaking 
through the littoral chain of Venezuela and the Sierra Parime. 
In Asia, shocks of earthquakes have been propagated from 
Lahore and from the foot of the Himalaya (22d of January, 
1832) transversely across the chain of the Hindoo Chou to 
Badakschan, the upper Oxus, and even to Bokhara. f The 
circles of commotion unfortunately expand occasionally in con- 
sequence of a single and unusually violent earthquake. It is 
only since the destruction of Cumana, on the 14th of Decem- 
ber, 1797, that shocks on the southern coast have been felt in 
the mica slate rocks of the peninsula of Maniquarez, situated 
opposite to the chalk hills of the main land. The advance 

* In Spanish they say, rocas qiie hacen puerde. With this phenome- 
non of non-propagation through superior strata is connected the remark 
able fact that in the beginning of this century shocks were felt in the 
deep silver mines at Marienberg, in the Saxony mining district, while 
not the slightest trace was perceptiblo at the surface. The miners 
ascended in a state of alarm. Couverijely, the workmen ia the mines 
of Falun and Persberg felt nothing of the shocks which in November, 
1823, spread dismay among the inhabitants above ground. 

t Sir Alex. Burnes, Travels in Bokhara, vol. i., p. 18; and Wathen, 
Mem. on the Ushek State, in the Journal o J the Asiatic Society uf Bengal, 
vol. iii., p. 337. 



EARTHaUAKES. 213 

♦roni south to north "was very striking in the almost uninter- 
rupted undulations of the soil in the alluvial valleys of the Mis- 
sissippi, the Arkansas, and the Ohio, from 1811 to 1813. It 
seemed here as if subterranean obstacles were gradually over- 
come, and that the way being once opened, the undulatory 
movement could be freely propagated. 

Although earthquakes appear at first sight to be simply dy- 
namic phenomena of motion, we yet discover, from well-at- 
tested facts, that they are not only able to elevate a whole dis- 
trict above its ancient level (as, for instance, the Ulla Bund, 
after the earthquake of Cutch, in June, 1819, east of the 
Delta of the Indus, or the coast of Chili, in November, 1822), 
but we also find that various substances have been ejected dur- 
ing the earthquake, as hot water at Catania in 1818 ; hot 
steam at New Madrid, in the Valley of the Mississippi, in 
1812 ; irrespirable gases, Mofettes, which injured the flocks 
grazing in the chain of the Andes ; mud, black smoke, and 
even flames, at Messina in 1781, and at Cum ana on the 14th 
of November, 1797. During the great earthquake of Lisbon, 
on the 1st of November, 1755, flames and columns of smoke 
were seen to rise from a newly-formed fissure in the rock of 
Alvidras, near the city. The smoke in this case became more 
dense as the subterranean noise increased in intensity. =^ At 
the destruction of Riobamba, in the year 1797, when the 
shocks were not attended by any outbreak of the neighboring 
volcano, a singular mass called the Moya was uplifted from 
the earth in numerous continuous conical elevations, the whole 
being composed of carbon, crystals of augite, and the silicious 
shields of infusoria. The eruption of carbonic acid gas from 
fissures in the Valley of the Magdalene, during the earthquake 
of New Granada, on the 16th of November, 1827, sufibcated 
many snakes, rats, and other animals. Sudden changes of 
weather, as the occurrence of the rainy season in the tropics, 
at an unusual period of the year, have sometimes succeeded 
violent earthquakes in Quito and Peru. Do gaseous fluids rise 
from the interior of the earth, and mix with the atmosphere % 
or are these meteorological processes the action of atmospheric 
electricity disturbed by the earthquake ] In the tropical re- 
gions of America, where sometimes not a drop of rain falls for 
ten months together, the natives consider the repeated shocks 
of earthquakes, which do not endanger the low reed huts, as 
auspicious harbingers of fruitfulness and abundant rain. 

* Philos. Transact., vol. xlix., p. 414. 



214 COSMOS. 

The intimate connection of the phenomena which we havt 
considered is still hidden in obscurity. Elastic fluids are doubt 
lessly the cause of the shght and perfectly harmless trembling 
of the earth's surface, which has often continued several daya 
(as in 1816, at Scaccia, in Sicily, before the volcanic eleva- 
tion of the island of Juha), as w^ell as of the terrific explosions 
accompanied by loud noise. The focus of this destructive agent, 
the seat of the moving force, lies far below the earth's surface ; 
but we know as little of the extent of this depth as we know 
of the chemical nature of these vapors that are so highly com- 
pressed. At the edges of two craters, Vesuvius, and the tow- 
ering rock which projects beyond the great abyss of Pichin- 
cha, near Quito, I have felt periodic and very regular shocks of 
earthquakes, on each occasion from 20 to 30 seconds before 
the burning scoriae or gases were erupted. The intensity of 
the shocks was increased in proportion to the time interven- 
ing betw^een them, and, consequently, to the length of time 
in which the vapors were accumulating. This simple fact, 
which has been attested by the evidence of so many travelers, 
furnishes us with a general solution of the phenomenon, in 
showing that active volcanoes are to be considered as safety- 
valves for the immediate neighborhood. The danger of earth- 
quakes increases when the openings of the volcano are closed, 
and deprived of free communication with the atmosphere ; but 
the destruction of Lisbon, of Caraccas, of Lima, of Cashmir in 
1554,* and of so many cities of Calabria, Syria, and Asia Mi- 
nor, shows us, on the whole, that the force of the shock is not 
the greatest in the ^leighborhood of active volcanoes. 

As the impeded activity of the volcano acts upon the shocks 
of the earth's surface, so do the latter react on the volcanic 
phenomena. Openings of fissures favor the rising of cones of 
eruption, and the processes which take place in these cones, 
by forming a free communication with the atmosphere. A 
column of smoke, which had been observed to rise for months 
together from the volcano of Paslo, in South America, sud- 
denly disappeared, when, on the 4th of February, 1797, the 
province of Quito, situated at a distance of 192 miles to the 
south, suffered from the great earthquake of Riobamba. After 
the earth had continued to tremble for some time through- 
out the whole of Syria, in the Cyclades, and in Euboea, the 
shocks suddenly ceased on the eruption of a stream of hot, mud 

* On the frequency of earthquakes in Cashmir, see Troyer's Geriiiai 
trauslation of the ancient Radjataringini, vol. ii., p. 297, and Car? v' 
Hiigel, Reisen, bd. ii., s. 184. 



earthuuakej?. 215 

on the Lelantine plains near Chalcis.* The intelligent geog-- 
rapher of Amasea, to whom we are indebted for the notice of 
this circumstance, further remarks : " Since the craters of iEtna 
have been opened, which yield a passage to the escape of fire, 
and since burning masses and water have been ejected, the coun- 
try near the sea-shore has not been so much shaken as at the 
time previous to the separation of Sicily from Lower Italy, when 
all communications with the external surface were closed." 

We thus recognize in earthquakes the existence of a vol- 
canic force, which, although every where manifested, and as 
generally diffused as the internal heat of our planet, attains 
but rarely, and then only at separate points, sufficient intensity 
to exbibit the phenomenon of eruptions. The formation of 
veins, that is to say, the filling up of fissures with crystalline 
masses bursting forth from the interior (as basalt, melaphyre, 
and greenstone), gradually disturbs the free intercommunica- 
tion of elastic vapors. This tension acts in three different 
ways, either in causing disruptions, or sudden and retroversed 
elevations, or, finally, as v>^as first observed in a great part of 
Sweden, in producing changes in the relative level of the sea 
and land, which, although continuous, are only appreciable at 
intervals of long period. 

Before we leave the important phenomena which we have 
considered, not so much in their individual characteristics as 
in their general physical and geognostical relations, I would 
advert to the deep and peculiar impression left on the mind by 
the first earthquake which we experience, even where it is not 
attended by any subterranean noise. f This impression is not, 

* Strabo, lib. i., p. 100, Casaub. That the expression 7n]Xov diaTTV- 
pov Ttora/jLov does not mean erupted mud, but lava, is obs'ious from a 
passage in Strabo, lib. vi., p. 412. Compare Walter, in his Abnahme der 
Vulkanischen Thutigkeit in Historischen Zeiten (On the Decrease of Vol- 
canic Activity during Historical Times), 1844, s. 25. 

+ [Dr. Tschudi, in his interesting work. Travels in Peru, translated 
from the German by Thomasina Ross, p. 170, 1847, describes striking- 
ly the effect of an earthquake upon the native and upon the stranger. 
" No familiarity with the phenomenon can blunt this feeling. The in- 
habitant of Lima, who from childhood has frequently witnessed these 
convulsions of nature, is roused from his sleep by the shock, and rushes 
from his apartment with the cry of Miaericordia ! The foreigner from 
the north of Europe, who knows nothing of earthquakes but by descrip 
tion, waits with impatience to feel the movement of the earth, and longs 
to hear with his own ear the subterranean sounds which he has hitherto 
considered fabulous. With levity he treats the apprehension of a com- 
ing convulsion, and laughs at the fears of the natives ; but, as soon as his 
wish is gratified, he is terror-stricken, and is involur.tarily prompted to 
seek s^ifety in flight."]— Tr. 



216 COSMOS. 

m my opinion, the result of a recollection of those fearful pic- 
tures of devastation presented to our imaginations by the his- 
torical narratives of the past, but is rather due to the sudden 
revelation of the delusive nature of the inherent faith by "which 
we had clung to a belief in the immobility of the solid parts 
of the earth. We are accustomed from early childhood to 
draw a contrast between the mobility of water an i the im- 
mobility of the soil on which we tread ; and this feeling is con- 
firmed by the evidence of our senses. When, therefore, we 
suddenly feel the ground move beneath us, a mysterious and 
natural force, with which we are previously unacquainted, is 
revealed to us as an active disturbance of stability. A moment 
destroys the illusion of a whole life ; our deceptive faith in the 
repose of nature vanishes, and we feel transported, as it were, 
into a realm of unknown destructive forces. Every sound — 
the faintest motion in the air — arrests our attention, and we 
no longer trust the ground on whigh we stand. Animals, es- 
pecially dogs and swine, participate in the same anxious dis- 
quietude ; and even the crocodiles of the Orinoco, which are 
at other times as dumb as our little lizards, leave the trem- 
bling bed of the river, and run with loud cries into the adjacent 
forests. 

To man the earthquake conveys an idea of some universal 
and unlimited danger. We may flee from the crater of a vol- 
cano in active eruption, or from the dwelling whose destruc- 
tion is threatened by the approach of the lava stream ; but in 
an earthquake, direct our flight whithersoever we will, we still 
feel as if we trod upon the very focus of destruction. This con- 
dition of the mind is not of long duration, although it takes its 
origin in the deepest recesses of our nature ; and when a se- 
ries of faint shocks succeed one another, the inhabitants of the 
country soon lose every trace of fear. On the coasts of Peru, 
where rain and hail are unknown, no Itss than the rolling 
thunder and the flashing lightning, these luminous explosions 
of the atmosphere are replaced by the subterranean noises 
which accompany earthquakes.* Long habit, and the very 

* [" Along the whole coast of Pefru the atmospheie is almost uni- 
formly in a state of repose. It is not illtiminated by the lightning's flash, 
or disturbed by the roar of the thunder; no deluges of rain, uo fierce 
hurricanes, destroy the fruits of the fields, and with them the hopes of 
the husbandman. But the mildness of the elements above ground ia 
frightfully counterbalanced by their subterranean fury. Lima is fre 
quently visited by earthquakes, and several times the city has been 
reduced to a mass of ruins. At an average, forty-five shocks may be 
counted on in the year. Mo^ of them occur in the latter part of Octo- 



GASEOUS EMANATIONS. 217 

pievalent opinion that dangerous shocks are only to be appre- 
hended two or three times in the course of a century, cause 
faint oscillations of the soil to be regarded in Lima with scarce- 
ly more attention than a hail storm in the temperate zone. 

Having thus taken a general view of the activity — the 
inner life, as it were — of the Earth, in respect to its internal 
heat, its electro-magnetic tension, its emanation of light at the 
poles, and its irregularly-recurring phenomena of motion, we 
will now proceed to the consideration of the material products, 
the chemical changes in the earth's surface, and the composi- 
tion of the atmosphere, which are all dependent on planetary 
vital activity. We see issue from the ground steam and 
gaseous carbonic acid, almost always free from the admixture 
of nitrogen ;* carbureted hydrogen gas, which has been used 
in the Chinese province Sse-tschuanf for several thousand 
years, and receiitly in the village of Fredonia, in the State of 
New York, United States, in cooking and for illumination ; 
sulphureted hydrogen gas and sulphurous vapors ; and, more 
rarely, $ sulphurous and hydrochloric acids. § Such effusions 

ber, in November, December, Jamiaiy, May, and June. Experience 
gives reason to expect the visitation of two desolating earthquakes in a 
century. The period betv^-eeu the tv^ro is from forty to sixty years. The 
most considerable catastrophes experienced in Lima since Europeans 
have visited the west coast of South America happened in the years 
1586, 1630, 1687, 1713, 1746, 1806. There is reason to fear that in the 
course of a few years this city may be the prey of another such visita- 
tion."— Tschudi, op. cit.]— -Tr. 

* Bischof's comprehensive work, Wdrmelehre des inneren Erdkorpers. 

t On the Artesian tire-springs (Ho-tsing) in China, and the ancient 
use of portable gas (in bamboo canes) in the city of Khiung-tsheu, see 
Klaproth, in my Asie Centrale, t. iii., p. 519-530. 

X Boussingault (Annates de Chimie, t. Hi., p. 181) observed no evolu- 
tion of hydrochloric acid from the volcanoes of New^ Granada, while 
Monticelli found it in euorijious quantity in the eruption of Vesuvius in 
1813. 

$ [Of the gaseous compounds of sulphur, one, sulphurous acid, ap- 
pears to predominate chiefly in volcanoes possessing a certain degree 
of activity, while the other, sulphureted hydrogen, has been most fre- 
quently perceived among those in a dormant condition. The occur- 
rence of abundant exhalations of sulphuric acid, which have been hith 
erto noticed chiefly in extinct volcanoes, as, for instance, in a stream 
issuing from that of Purace, between Bogota and Quito, from extinct 
volcanoes in Java, is satisfactorily explained in a recent paper by M. 
Dumas, Annales de Chimie, Dec, 1846. He shows that when sulphu- 
reted hydrogen, at a temperature above 100° Fahr., and still better 
when near 190°, comes in contact with certain porous bodies, a cata- 
lytic action is set up, by which water, sulphuric acid, and sulphur are 
produced. Hence probably the vast deposits of sulphur, associated 
with sulphates of lime and strontiau, which are met with in the 
western parts of Sicilv.] — Tr. 

Vol. I— K. 



218 COSMOS. 

from the fissures of the earth not only occur in the districts 
of stiil burning or long-extinguished volcanoes, but they may 
likewise be observed occasionally in districts where neither 
trachyte nor any other volcanic rocks are exposed on the 
earth's surface. In the chain of Quindiu I have seen sul- 
phur deposited in mica slate from Avarm sulphurous vapor 
at an elevation of 6832 feet^ above the level of the sea, 
while the same species of rock, which was formerly regarded 
as primitive, contains, in the Cerro Cuello, near Tiscan, south 
of Quito, an immense deposit of sulphur imbedded in pure 
quartz. 

Exhalations of carbonic acid (inofettes) are even in our days 
to be considered as the most important of all gaseous emana- 
tions, with respect to their number and the amount of their 
effusion. We see in Germany, in the deep valleys of the 
Eifel, in the neighborhood of the Lake of Laach,t in the 
crater-like valley of the Wehr and in Western Bohemia, ex- 
halations of carbonic acid gas manifest themselves as the last 
etlbrts of volcanic activity in or near the foci of an earlier 
world. In those earlier periods, when a higher terrestrial 
temperature existed, and when a great rmmber of fissures 
still remained unfilled, the processes we have described acted 
more powerfully, and carbonic acid and hot steam were mixed 
in larger quantities in the atmosphere, from whence it follows, 
as Adolph Brongniart has ingeniously shown,| that the primi- 
tive vegetable world must have exhibited almost every where, 
and independently of geographical position, the most luxurious 
abundance and the fullest development of organism. In these 
constantly warm and damp atmospheric strata, saturated with 

."^ Hiiia'ooldt, Recucil cfObserv. Asironomiques, t. i., p. 311 (Nivelle 
meat Barometrique de la Cordillere des Andes, No. 206). 

t [The Lake of Laacb, in the district of the Eifel, is an expanse of 
water two miles in circumference. The thickness of the vegetation on 
the sides of its crater-like basin renders it difficult to discover the nature 
of the subjacent rock, but it is probably composed of black cellular 
au<<itic lava. The sides of the crater present numerous loose masses, 
which appear to have been ejected, and consist of glassy feldspar, ice- 
spar, sodalite, hauyne, spinellane, and leucite. The resemblance be- 
tween these products and the masses formerly ejected from Vesuvius is 
most remarkable. (Uaubeney On Volcanoes, p. 81.) Dr. Hibbert re- 
gards the Lake of Laach as formed in the first instance by a crack 
caused by the cooling of the crust of the earth, which was widened 
afterward into a circular cavity by the expansive force of elastic vapoi's. 
See History of the Extinct Volcanoes of the Basin of Neutoied, 1832.] 
— Tr. 

t Adolph Brongniart, in the AnnaJes des Sciences Noturclles. t. xv., 
p. 225. 



GArfEOUS EMANATIONS. 219 

carbonic acid, vegetation must have attained a degree of vital 
activity, and derived the superabundance of nutrition necessary 
to furnish materials for the formation of the beds of hgnite 
(coal), constituting the inexhaustible means on which are based 
the physical power and prosperity of nations. Such masses 
are distributed in basins over certain parts of Europe, occur- 
ring in large quantities in the British Islands, in Belgium, i,n 
France, in the provinces of the Lower Rhine, and in Upper 
Silesia. At the same primitive period of universal volcanic 
activity, those enormous quantities of carbon must also have 
escaped from the earth which are contained in limestone 
rocks, and which, if separated from oxygen and reduced to a 
solid form, would constitute about the eighth part of the abso- 
lute bulk of these mountain masses.* That portion of the 
carbon which was not taken up by alkaline earths, but re- 
mained mixed with the atmosphere, as carbonic acid, was 
gradually consumed by the vegetation of the earlier stages of 
the world, so that the atmosphere, after being purified by the 
processes of vegetable life, only retained the small quantity 
which it now possesses, and which is not injurious to the 
present organization of animal life. Abundant eruptions of 
sulphurous vapor have occasioned the destruction of the spe- 
cies of moUusca and fish which inhabited the inland waters of 
the earlier world, and have given rise to the formation of the 
contorted beds of gypsum, which have doubtless been fre- 
quently affected by shocks of earthquakes. 

Gaseous and liquid fluids, mud, and molten earths, ejected 
from the craters of volcanoes, which are themselves only a 
kind of " intermittent springs,^^ rise from the earth under pre- 
cisely analogous physical relations.! All these substances owe 
their temperature and their chemical character to the place 
of their origin. The mean temperature of aqueous springs is 
less than that of the air at the point whence they emerge, if 
the water flow from a height ; but their heat increases with 
the depth of the strata with which they are in contact at their 
origin. We have already spoken of the numerical law regu- 
latinof this increase. The blendinjj of waters that have come 
from the height of a mountain with those that have sprung 
from the depths of the earth, render it difficult to determine 
the position of the isogeothermal li?iesX (lines of equal internal 

* Bischof, op. cit., s. 324, Anm. 2. 
t Humboldt, Asie Centrale, t. i., p. 43. 

X Ou the theory of isogeothermal (chthonisothermal) Imes, consult the 
ingenious labors of Kupfter, in Pog^'., Atmalen, bd xv., s. 184, and bd 



220 COSMOS. 

terrestrial temperature), Avhen this determination is to be 
made from the temperature of flowing springs. Such, at any 
rate, is the result I have arrived at from my ov^n observations 
and those of my fellow-travelers in Northern Asia. The 
temperature of springs, which has become the subject of such 
continuous physical investigation during the last half century, 
depends, like the elevation of the line of perpetual snow, on 
very many simultaneous and deeply- involved causes. It is a 
function of the temperature of the stratum in which they take 
their rise, of the specific heat of the soil, and of the quantity 
and temperature of the meteoric water,* which is itself dif- 
ferent from the temperature of the lower strata of the atmos- 
phere, according to the different modes of its origin in rain, 
snow, or hail.f 

Cold springs can only indicate the mean atmospheric tem- 

xxxii., s. 270, in the Voyage dans V Oural, p. 382-398, and in the 
Edinburgh Journal of Science, New Series, vol. iv., p. 355. See, also, 
Kamtz, Lehrb. der Meteor., bd. ii., s. 217; and, on the ascent of the 
chthonisothermal lines in mountainous districts, Bischof, s. 174-198. 

* Leop. V. Buch, in Pogg., Annalen, bd. xii., s. 405. 

t On the temperature of the drops of rain in Cumana, which fell to 
72°, when the temperature of the air shortly before had been 86° and 
88°, and during the i-ain sank to 74°, see my Relat. Hist., t. ii., p. 22. 
The rain-drops, while falling, change the normal temperature they 
originally possessed, which depends on the height of the clouds from 
which they fell, and their heating on their upper surface by the solar 
rays. The rain-drops, on their first production, have a higher tempera- 
ture than the surrounding medium in the superior strata of our atmos- 
phei-e, in consequence of the liberation of their latent heat ; and they 
continue to rise in temperature, since, in falling through lower and 
warmer strata, vapor is precipitated on them, and they thus increase in 
size (Bischof, Wdrmelehre des imieren Erdkorpers, s. 73) ; but this ad- 
ditional heating is compensated for by evaporation. The cooling of the 
air by rain (putting out of the question what probably belongs to the 
electric process in storms) is effected by the drops, which are them- 
selves of lower temperature, in consequence of the cold situation in 
which they were formed, and bring down w^ith them a portion of the 
higher colder air, and which finally, by moistening the ground, give 
rise to evaporation. These are the ordinary relations of the phenome- 
non. When, as occasionally happens, the rain-drops are warmer than 
the lower strata of the atmosphere (Humboldt, Rel. Hist., t. iii., p. 
513), the cause must probably be sought in higher warmer currents, or 
in a higher temperature of widely-extended and not very thick clouds, 
from the action of the sun's rays. How, moreover, the phenomenon of 
supplementary rainbows, which are explained by the interference of 
light, is connected with the original and increasing size of the falling 
drops, and how an optical phenomenon, if we know how to observe it 
accurately, may enlighten us regarding a meteorological process, ac- 
cording to diversity of zone, has been shown, with much talent and in 
genuity, by Arago, in the Annuaire for 1836, p. 300- 



HOT SPRINGS. 



221 



perature when they are unmixed with the waters rising from 
great depths, or descending from considerable mountain eleva- 
tions, and when they have passed through a long course at a 
depth from the surface of the earth which is equal in our lati- 
tudes to 40 or 60 feet, and, according to Boussingault, to about 
one foot in the equinoctial regions ;* these being the depths at 
which the invariability of the temperature begins in th^ tem- 
perate and torrid zones, that is to say, the depths at which 
horary, diurnal, and monthly changes of heat in the atmosphere 
cease to be perceived. 

Hot springs issue from the most various kinds of rocks. The 
hottest permanent springs that have hitherto been observed 
are, as my own researches confirm, at a distance from all vol- 
canoes. I will here advert to a notice in my journal of the 
Aguas Calie7ites de las Trincheras, in South America, between 
Porto Cabello and Nueva Valencia, and the Aguas de Coman- 
gillas, in the Mexican territory, near Guanaxuato ; the for- 
mer of these, which issued from granite, had a temperature of 
194°-5; the latter, issuing from basalt, 205°-5. The depth 
)f the source from whence the water flowed with this temper- 
ature, judging from v/hat we know of the law of the increase 
of heat in the interior of the earth, was probably 7140 feet, 
or above two miles. If the universally-difilised terrestrial 
heat be the cause of thermal springs, as of active volcanoes, 
the rocks can only exert an influence by their difTerent capaci- 



" The profound investigations of Boussingault fully convince me, that 
in the tropics, tlie temperature of the ground, at a very slight depth, ex 
actly corresponds witli the mean temperature of the air. The follow 



ing uistauces are sufficient to ilhistrate this fact : 



Stations witbia Tropical Zones. 


Temperature at 1 French 
foot [l-00r> of the Englisli 
foot] below the earth's 
surface. 


Mean Temper- Height, in Enghsh 
ature of the feet, above the 
air. level of the sea. 


Guayaquil 

Anserma Nuevo 

Zupia . 


78-8 
74-6 
70-7 
64-7 
59-9 


78-1 1 
74-8 3444 
70-7 4018 
65-6 " ! 5929 
59-9 ' 9559 


Popayan 


Quito 





The doubts about the temperature of the earth within the tropics, of 
wliich I am probably, in some degree, the cause, by my observations 
oh the Cave of Caripe (Cueva del Guacharo^), Rel. Hist., t. ii:., p. 191- 
196), are resolved by the consideration that I compared the presumed 
mean temperature of the air of the convent of Caripe, G5°*3, not with 
the temperature of the air of the cave, G5°-G, but vs'ith tlje temperature 
of the subterranean stream, G2'^*3, although I ob.served {Rel. Hist., t 
iii., p. 146 and 194) that mountain water from a gre.it heigh 
probably be mixed wilh the water of the cave 



t might 



222 COSMOS. 

ties for heat and by tlieir conducting powers. The hottest of 
all permanent springs (between 203^ and 209°) are likewise, 
in a most remarkable degree, the purest, and such as hold in 
solution the smallest quantity of mineral substances. Their 
temperature appears, on the whole, to be less constant than 
that of springs between 122° and 165°, which in Europe, at 
least, "have maintained, in a most remarkable manner, their 
hivariabilitif of heat and inineral contents during the last 
fifty or sixty years, a period ih which thermometrical measure- 
ments and chemical analyses have been applied with increas- 
ed exactness. Boussingault found in 1823 that the thermal 
springs of Las Trincheras had risen 12° during the twenty- 
three years that had intervened since my travels in 1600.* 
This calmly- flowing spring is therefore now nearly 12° hotter 
than the intermittent fountains of the Geyser and the Strokr, 
whose temperature has recently been most carefully determ- 
ined by Krug of Nidda. A very striking proof of the origin 
of hot springs by the sinking of cold meteoric M'ater into the 
earth, and by its contact with a volcanic focus, is afibrded by 
the volcano of JoruUa in Mexico, which was unknown before 
my American journey. When, in September, 1759, Jorullo 
\was suddeidy elevated into a mountain 1183 feet above the 
level of the surrounding plain, two small rivers, the Rio de 
Cuitimba and Rio de San Pedro, disappeared, and some 
time afterward burst forth ajjain, durinjf violent shocks of an 
earthquake, as hot springs, whose temperature I found in 1803 
to be 186°-4. 

The springs in Greece still evidently flow at the same places 
as in the times of Hellenic antiquity. The spring of Erasinos, 
two hours' journey to the south of Argos, on the declivity of 
Chaon, is mentioned by Herodotus. At Delphi we still see 
Cassotis (now the springs of St. Nicholas) rising south of the 
Lesche, and flowing beneath the Temple of Apollo ; Castaiia, 
at the foot of PhsedriadiB ; Pirene, near Acro-Corinth ; and 
the hot baths of ^dipsus, in Euboea, in which Sulla bathed 
during the Mithridatic war.f I advert with pleasure to these 

* Boussingault, in the Annales de Chimie, t. lii., p. 181. The spring 
of Chaudes Aigues, in Auvergne, is only 176°. It is also to be observ- 
ed, that while the Aguas Calieutes de las Trincheras, south of Porto 
Cabello (Venezuela), springing from granite cleft in regular beds, and 
far from all volcanoes, have a temperature of fully 206°'6, all the springs 
which rise in the vicinity of still active volcanoes (Pasto, Cotopaxi, and 
Tunguragua) have a temperature of only 97'~'-130°. 

t Cassotis (the spring of St. Nicholas) and Castaiia, at the Phaedriad;e, 
mentioned in Pausanias, x., 24, 25, and x., 8, 9 ; Pirene (Acro-Corinth), 



HOT SPRINGS, '223 

iacls, as they show us that, even in a country subject to fre- 
quent and violent shocks of earthquakes, the interior of our 
planet has retained for upward of 2000 years its ancient con- 
figuration in reference to the course of the open fissures that 
yield a passage to these waters. The Fontaine jaillusante of 
Lillers, in the Department des Pas de Calais, which was bored 
as early as the year 1126, still rises to the same height and 
yields the same quantity of water ; and, as another instance, I 
may mention that the admirable geographer of the Carama- 
nian coast. Captain Beaufort, sa\v in the district of Phaselis the 
same flame fed by emissions of inflammable gas which was de- 
scribed by Pliny as the flame of the Lycian Chimera.* 

The observation made by Arago in 1821, that the deepest 
Artesian wells are the warmest,! threw great light on the ori- 
gin of thermal springs, and on the' establishment of the law 
that terrestrial heat increases with increasing depth. It is a 
remarkable fact, which has but recently been noticed, that at 
the close of the third century, St. Patricius,| probably Bishop 
of Pertusa, was led to adopt very correct views regarding the 
phenomenon of the hot springs at Carthage. On being asked 
^yhat was the cause of boiling water bursting from the earth, 
he replied, " Fiire is nourished in the clouds and in the interior 

ill Strabo, p. 379 ; the spring of Erasinos, at Mount Chaoii, south of Ar- 
gos, iu Herod., vL, 67, and Fausanias, ii., 24, 7 ; the springs of iEdipsus 
in Eubcea, some of which have a tempei'ature of 88°, while in others it 
ranges between 144° and 167°, in Sli'abo, p. 60 and 447, and Atheuaeu*, 
ii-, 3, 73 ; the hot springs of Thermopyke, at the foot of CEta, with a 
temperature of 149°. All from manuscript notes by Professor Curtius, 
the learned companion of Otfried Mtiller. 

"^ Pliny, ii., 106; Seneca, Episf... 79, § 3, ed. Ruhkopf (Beaufort, /S«r. 
vcj/ of the Coast of Karamania, 1820, art. Yanar, near Deliktasch, the 
ancient Phasehs, p. 24). See, also, Ctesias, Fragm., cap. 10 p. 250, 
ed- Bahr; Strabo, lib. xiv., p. 666, Casaab. 

[" Not far from the Dehktae-h, on the side of a mountain, is tlie per- 
petual fire described by Captain Beaufort. The travelers found it as 
brilliant as ever, and even somewhat increased ; for, besides the large 
flame in the corner of the ruins described by Beaufort, there were small 
jets issuing from crevices in the side of tlie crater-like cavity five or 
six feet deep. At the bottom was a shallow pool of sulphureous and 
turbid water, regarded by the Turks as a sovereign remedy for all skin 
complaints. The soot deposited from the flames was regarded as effi- 
cacious for sore eyelids, and valued as a dye for the eyebrows." See 
the highly interesting and accurate work, Travels in Lycia, by Lieut. 
Sptatt and Professor E. Forbes.] — Tr. 

t Arago, in the Anmiaire pour 183.5, p. 234. 

X Acta S. Patricii, p. 55.5, ed. Ruinart, t. ii.. p. 385, Mazochi. Dn- 
reau de la M.iUe was the first to dr-nw attention to this remarkable pas- 
sage iu the Recherches s)ir la Top>graphic de Cnrthage, 18-?5. p. 276. 
(See, aUi), Seneoi. N-it- Qmrsf.. iii.. 24.) 



221 COSMOS. 

of the earth, as .^tna and other mountains near Naples may 
teach you. The subterranean waters rise as if through si- 
phons. The cause of hot springs is this : waters which are 
more remote from the subterranean fire are colder, while those 
which rise nearer the fire are heated by it, and bring with 
them to the surface which we inhabit an insijpportable degree 
of heat." 

As earthquakes are often accompanied by eruptions of water 
and vapors, we recognize in the Salses,^ or small mud vol- 
canoes, a transition from the changing phenomena presented 
by these eruptions of vapor and thermal springs to the more 
powerful and awful activity of the streams of lava that flow 
from volcanic mountains. If we consider these mountains as 
springs of molten earths producing volcanic rocks, we must re- 
member that thermal waters, when impregnated with carbonic 
acid and sulphurous gases, are continually forming horizon- 
tally ranged strata of limestone (travertine) or conical eleva- 
tions, as in Northern Africa (in Algeria), and in the Bancs 
of Caxamarca, on the western declivity of the Peruvian Cor- 
dilleras. The travertine of Van Diemen's Land (near Hobart 
Town) contains, according to Charles Darwin, remains of a 
vegetation that no longer exists. Lava and travertine, which 
are constantly forming before our eyes, present us with the 
two extremes of geognostic relations. 

Salses deserve more attention than they have hitherto re- 
ceived from geognosists. Their grandeur has been overlooked 
because of the two conditions to which they are subject ; it is 
only the more peaceful state, in which they may continue for 
centuries, which has generally been described : their origin is, 
however, accompanied by earthquakes, subterranean thunder, 
the elevation of a whole district, and lofty emissions of flame 
of short duration. When the mud volcano of Jokmali began 
to form on the 27th of November, 1827, in the peninsula of 
Abscheron, on the Caspian Sea, east of Baku, the flames 
flashed up to an extraordinary height ibr three hours, while 
during the next twenty hours they scarcely rose three feet 
above the crater, from which mud was ejected. Near the 
village of Baklichli, west of Baku, the flames rose so high that 

* [True volcanoes, as we have seen, generate sulpbureted hydrogen 
and muriatic acid, upheave tracts of land, and emit streams of melted 
feldapathic materials ; salses, on the contrary, disengage little else but 
carbm-eted hydrogen, together with bitumen and other products of the 
distillation of coal, and pour forth no other torrents except of mud, oj 
argillaceous materials mixed up with water. Daubeney, op cit., p 
510.]— Tr. 



SALSES. - 225 

they could be seen at a distance of twenty-four miles. Enor- 
mous masses of rock were torn up and scattered arounfl. Sim- 
ilar masses may be seen round the now inactive mud volcano 
of Monte Zibio, near Sassuolo, in Northern Italy. The sec- 
ondary condition of repose has been maintained for upward of 
fifteen centuries in the mud volcanoes of Girgenti, the Maca- 
lubi, in Sicily, which have been described by the ancients. 
These salses consist of many contiguous conical hills, from 
eight to ten, or even thirty feet in height, subject to variations 
of elevation as well as of form. Streams of argillaceous mud, 
attended by a periodic development of gas, flow from the small 
basins at the summits, which are filled with water ; the mud, 
although usually cold, is sometimes at a high temperature, as 
at Damak, in the province of Samarang, in the island of Java. 
The gases that are developed with loud noise differ in their 
nature, consisting, for instance, of hydrogen mixed with naph- 
tha, or of carbonic acid, or, as Parrot and myself have shown 
(in the peninsula of Taman, and in the Volcancitos de Tur- 
baco, in South America), of almost pure nitrogen.* 

Mud volcanoes, after the first violent explosion of fire, which 
is not, perhaps, in an equal degree common to all, present to 
the spectator an image of the uninterrupted but weak activity 
of the interior of our planet. The communication with the 
deep strata in which a high temperature prevails is soon closed, 
and the coldness of the mud emissions of the salses seems to in- 
dicate that the seat of the phenomenon can not bo far re- 
moved from the surface during their ordinary condition. The 
reaction of the interior of the earth on its external surface is 
exhibited with totally different force in true volcanoes or igne- 
ous mountains, at points of the earth in which a permanent, 
or, at least, continually-renewed connection with the volcanic 
force is manifested. We must here carefully distinguish be- 
tween the more or less intensely developed volcanic phenom- 
ena, as, for instance, between earthquakes, thermal, aqueous, 
and gaseous springs, mud volcanoes, and the appearance of 
bell-formed or dome-shaped trachytic rocks without openings ; 
the opening of these rocks, or of the elevated beds of basalt, as 

* Hamboldt, Rel. Hist., t. iii., p. 562-567 ; Asie Centrale, t. i., p. 43 ; 
t. ii., p. 505-515; Vues des Cordilleres, pi. xli. Regarding the Maca- 
lubi (the Arabic Makhlub, the overthrown or inverted, from the word 
Khalaba), and on " the Earth ejecting fluid earth," see Solinus, cap. 5: 
"idem ager Agrigentinus eructat limosas scatm-igenes, et ut venae fon- 
tium sufEciunt rivis subministrandis, ita in hac Siciliae parte solo nun- 
Quam deficiente, aeterna rejectatione terrara terra evomit." 

K 2 



226 COSMOS. 

craters of elevation ; and, lastly^the elevation of a permanent 
volcano in the crater of elevation, or among the debris of its 
earlier formation. At different periods, and in different de- 
grees of activity and force, the permanent volcanoes emit 
steam, acids, luminous scorise, or, w^hen the resistance can be 
overcome, narrow, band-like streams of molten earths. Elas- 
tic vapors sometimes elevate either separate portions of the 
earth's crust into dome-shaped unopened masses of feldspathic 
trachyte and dolerite (as in Puy de Dome and Chimborazo), 
in consequence of some great or local manifestation offeree in 
the interior of our planet, or the upheaved strata are broken 
through and curved in such a manner as to form a steep rocky 
ledge on the opposite inner side, vv^hich then constitutes the in- 
closure of a crater of elevation. If this rocky ledge has been 
uplifted from the bottom of the sea, which is by no means al- 
ways the case, it determines the whole physiognomy and form 
of the island. In this manner has arisen the circular form of 
Palma, which has been described with such admirable accu- 
racy by Leopold von Buch, and that of Nisyros,* in the /Egean 
Sea. Sometimes half of the annular ledge has been destroy- 
ed, and in the bay formed by the encroachment of the sea cor- 
allines have built their cellular habitations. Even on conti- 
nents craters of elevation are often filled with water, and em- 
bellish in a peculiar manner the character of the landscape. 
Their origin is not connected with any determined species of 
rock : they break out in basalt, trachyte, leucitic porphyry 
(somma), or in doleritic mixtures of augite and labradorite ; 
and hence arise the different nature and external conformation 
of these inclosures of craters. No phenomena of eruptions are 
manifested in such craters, as they open no permanent channel 
of communication with the interior, and it is but seldom that 
we meet with traces of volcanic activity either in the neigh- 
borhood or in the interior of these craters. The force which 
was able to produce so important an action must have been 
long accumulating in the interior before it could overpower the 
resistance of the mass pressing upon it ; it sometimes, for in- 
stance, on the origin of new islands, will raise granular rocks 
and conglomerated masses (strata of tufa filled with marine 
plants) above the surface of the sea. The compressed vapors 
escape through the crater of elevation, but a large mass soon 
falls back and closes the opening, which had been only formed 
by these manifestations of force. No volcano can, therefore, 

* See the interesting little map of the island of Nit^yros, in Ross's 
Reisen auf den Griechischen Inseln, bd. ii., 1843, s. 69. 



VOLCANOES. 227 

be produced.* A volcano, properly so called, exists only where 
a permanent connection is established between the interior of 
the earth and the atmosphere, and the reaction of the interior 
on the surface then continues during long periods of time. It 
may be interrupted for centuries, as in the case of Vesuvius, 
Fisove,t and then manifest itself with renewed activity. In 
the time of Nero, men were disposed to rank ^tna among 
the volcanic mountains which were gradually becoming ex- 
tinct ,t and subsequently ^lian^ even maintained that mar- 
uiers could no longer see the sinking summit of the mountain 
from so great a distance at sea. AVhere these evidences — 
these old. scaffoldings of eruption, I might almost say — still 
exist, the volcano rises from a crater of elevation, while a high 
rocky wall surrounds, like an amphitheater, the isolated con- 
ical mount, and forms around it a kind of casing of highly ele- 

* Leopold von Buch, Phys. Besckreibung der Canarischen Inselti, s. 
326; and his Memoir uber Erhebungscratere und Vulcane, in Poggend., 
AnnaL, bd. xxxvii., s. 169. 

In his remarks on the separation of Sicily from Calabria, Strabo gives 
an excellent description of the two modes in which islands are formed: 
"Some islands," he observes (lib. vi., p. 258, ed. Casaub.), "are frag- 
ments of the continent, others have arisen from the sea, as even at the 
present time is known to happen ; for the islands of the great ocean, 
lying far from the main land, have probably been raised from its depths, 
while, on the other hand, those near promontories appear (according to 
reason) to have been separated from the continent." 

t Ocre Fisove (Mons Vesuvius) in the Umbrian language. (Lassen, 
Deutung der Engubinischen Tafeln in Rhein. Museum, 1832, s. 387.) 
The w^ord ochre is very probably genuine Umbrian, and means, accord- 
ing to Yeslus,, mountain, ^tna would be a burning and shining mount* 
ain, if Voss is coiTect in stating that klrvrj is an Hellenic sound, and is 
connected with aWu and aldLvog; but the intelligent writer Parthey 
doubts this Hellenic origin on etymological grounds, and also because 
^tua was by no means regarded as a luminous beacon for ships or 
wanderers, in the same manner as the ever-travailing Stroraboli (Stron- 
gyle), to which Homer seems to refer in the Odyssey (xii., 68, 202, 
and 219), and its geographical position was not so well determined. I 
suspect that ^tna would be found to be a Sicilian word, if we had any 
fragmentary materials to refer to. According to Diodorus (v., 6), the 
Sicani, or aborigines preceding the Sicilians, were compelled to tiy to 
the western part of the island, in consequence of successive erui)tion8 
extending over many years. The most ancient eruption of INIouut ^Etna 
on record is that mentioned by Pindar and ^Eschylus, as occurring un- 
der Hiero, in the second year of the 75th Olympiad. It is probable 
that Hesiod was aware of the devastating eruptions of iEtna before the 
period of Gree.k immigration. There is. however, some doubt regard- 
ing the word AItvtj in the text of Hesiod, a subject into which I have 
entered at some length in another place. (Humboldt, Examen Crit. 
de le Geogr., t. i., p. 1G8.) 

t Seneca. Epist., 79. $ .Lilian, Var. Hi^t.. yiii.. i < 



22S COSMOS. 

vated strata. Occasionally not a trace of this mclosure is 
visible, and the volcano, which is not always conical; rises 
immediately from the neighboring plateau in an elongated 
form, as in the case of Piehincha,* at the foot of which lies 
the city of Quito. 

As the nature of rocks, or the mixture (grouping) of simple 
minerals into granite, gneiss, and mica slate, or into trachyte, 
basalt, and dolorite, is independent of existing climates, and is 
the same under the most varied latitudes of the earth, so also 
we find every where in inorganic nature that the same laws of 
configuration regulate the reciprocal superposition of the strata 
of the earth's crust, cause them to penetrate one another in 
the form of veins, and elevate them by the agency of elastic 
forces. This constant recurrence of the same phenomena is 
most strikingly manifested in volcanoes. When the mariner, 
amid the islands of some distant archipelago, is no longer guid- 
ed by the light of the same stars with which he had been fa- 
miliar in his native latitude, and sees himself surrounded by 
palms and other forms of an exotic vegetation, he still can 
trace, reflected in the individual characteristics of the land- 
scape, the forms of Vesuvius, of the dome-shaped summits of 
Auvergne, the craters of elevation in the Canaries and Azores, 
or the fissures of eruption in Iceland. A glance at the satel- 
lite of our planet will impart a wider generalization to this anal- 
ogy of configuration. By means of the charts that have been 
drawn in accordance with the observations made with large 
telescopes, we may recognize in the moon, where water and air 
are both absent, vast craters of elevation surrounding or sup- 
porting conical mountains, thus affording incontrovertible evi- 
dence of the effects produced by the reaction of the interior on 
the surface, favored by the influence of a feebler force of grav- 
itation. 

Although volcanoes are justly termed in many languages 
"fire-emitting mountains," mountains of this kind are not 
formed by the gradual accumulation of ejected currents of 
lava, but their origin seems rather to be a general consequence 
of the sudden elevation of soft masses of trachyte or labrador- 
itic augite. The amount of the elevating force is manifested 

* [This mountain contains two funnel-shaped craters, apparently re- 
sulting from two sets of eruptions: the western nearly circular, ?nd 
having in its center a cone of eruption, from the summit and sides of 
which are no less than seventy vents, some in activity and others ex- 
tinct. It is probable that the larger number of the vents were })!'t) 
duced at periods anterior to history, Daubeney, op. cit., p. 488-] — V'-- 



VOLCANOES. 229 

by the elevation of the volcano, which varies from the incon- 
siderable height of a hill (as the volcano of Cosima, one of the 
Japanese Kurile islands) to that of a cone above 19,000 feet 
in height. It has appeared to nie that relations of height have 
a great influence on the occurrence of eruptions, which are 
more frequent in low than in elevated volcanoes. I might in- 
stance the series presented by the following mountains : Strom- 
boh, 2318 feet ; Guacamayo, in the province of Quixos, from 
which detonations are heard almost daily (I have myself often 
heard them at Chillo, near Quito, a distance of eighty-eight 
miles); Vesuvius, 3876 feet; -^tna, 10,871 feet; the Peak 
of Tenerifie, 12,175 feet; and Cotopaxi, 19,069 feet. If the 
focus of these volcanoes be at an equal depth below the sur- 
face, a greater force must be required where the fused masses 
have to be raised to an elevation six or eight times greater 
than that of the lower eminences. While the volcano Strom- 
boli (Strongyle) has been incessantly active since the Homeric 
ages, and has served as a beacon-light to guide the mariner in 
the Tyrrhenian Sea, loftier volcanoes have been characterized 
by long intervals of quiet. Thus we see that a whole century 
often intervenes between the eruptions of most of the colossi 
which crown the summits of the Cordilleras of the Andes. 
Where we meet with exceptions to this law, to which I long 
since drew attention, they mufet depend upon the circumstance 
that the connections between the volcanic foci and the crater 
of eruption can not be considered as equally permanent in the 
case of all volcanoes. The channel of communication may be 
closed for a time in the case of the lower ones, so that they 
less frequently come to a state of eruption, although they do 
not, on that account, approach more nearly to their final ex- 
tinction. 

These relations between the absolute height and the fre- 
quency of volcanic eruptions, as far as they are externally per 
ceptible, are intimately connected with the consideration of 
the local conditions under which lava currents are erupted. 
Eruptions from the crater are very unusual in many mount- 
ains, generally occurring from lateral fissures (as was observed 
in the case of ^tna, in the sixteenth century, by the cele- 
brated historian Bembo, when a youth^), wherever the sides 

* Petri Bembi Opuscula {^tna Dialogus), Basil, 1556, p. 63 : " Quic- 
quid ill iEtnae matris utero coalescit, nunqiiam exit ex cratere superiore, 
quod vol eo iuscondere gravis materia noii queat, vel, quia iuferius alia 
Bpirameuta sunt, nou fit opus. Despumant flammis urgeutibus iguei rivi 
pigro fluxu Iotas delarabentes plagas, et in lapidem indurescunt." 



230 COSMOS. 

of the upheaved mountain were least ahle, from their configu- 
ration and position, to offer any resistance. Cones of eruption 
are sometimes uplifted on these fissures ; the .larger ones, which 
are erroneously termed iieiv volcmioes, are ranged together in a 
line marking the direction of a fissure, which is soon reclosed, 
while the smaller ones are grouped together, covering a whole 
district with their dome-like or hive-shaped forms. To the 
latter belong the homitos de Jorullo,^ the cone of Vesuvius 
erupted in October, 1822, that of Awatscba, according to Pos- 
tels, and those of the lava-field mentioned by Erman, near the 
Baidar Mountains, in the peninsula of Kamtschatka. 

When volcanoes are not isolated in a plain, but surrounded, 
as in the double chain of the Andes of Quito, by a table-land 
having an elevation from nine to thirteen thousand feet, this 
circumstance may probably explain the cause why no lava 
streams are formedf during the most dreadful eruption of ig- 
nited scoriae accompanied by detonations heard at a distance 
of more than a hundred miles. Such are the volcanoes of Po- 
payan , those of the elevated plateau of Los Pastes and of the 
Andes of Quito, with the exception, perhaps, in the case of 
the latter, of the volcano of Antisana. The height of the cone 
of cinders, and the size and form of the crater, are elements 
of configuration which yield an especial and individual char- 
acter to volcanoes, although the cone of cinders and the crater 
are both wholly independent of the dimensions of the mount- 
ain. Vesuvius is more than three times lower than the Peak 
of Tenerifle ; its cone of cinders rises to one third of the height 
of the whole mountain, while the cone of cinders of the Peak 
is only -^-^di of its altitude. | In a much higher volcano than 
that of Teneriffe, the Rucu Pichincha, other relations occur 

* See my drawing of the volcano of .Torullo, of its homitos, and of the 
uplifted malpays, in my Viies de Cordilleres, pi. xliii., p. 239. 

[Burckhardt states that during the twenty-four years that have inter- 
vened since Baron Humboldt's visit to Jorullo, the homitos have either 
wholly disappeared or completely changed their forms. See Aufenthalt 
und Reisen in Mexico in 1825 und 1834.] — Tr. 

\ Humboldt, £ssai sur la Giogr. desPtantes et Tableau Phys. des R6- 
gions Equinoxiales, 1807, p. 130, and Essai Geogn. snr le Gisement des 
Roches, p. 321. Most of the volcanoes in Java demonstrate that the 
cause of the perfect absence of lava streams in volcanoes of incessant 
activity is not alone to be sought for in their form, position, and height. 
Leop. von Buch, Descr. Phys. des lies Canaries, p. 419 ; Reinwardt and 
Hoffmann, in Poggend., Annalen., bd. xii., s. C07. 

\ [It may be remarked in general, although the rule is liable to ex- 
ceptions, that the dimensions of a crater are in an inverse ratio to the 
elevation of the mountain. Daubeuey, op. cit., p. 444.] — Tr. 



VOLCANOES. 231 

wliicli approach more nearly to that of Vesuvius. Among all 
the volcanoes that I have seen iu the two hemispheres, the 
conical form of Cotopaxi is the most beautifully regular. A 
sudclen fusion of the snow at its cone of cinders announces the 
proximity of the eruption. Before the smoke is visible in the 
rarefied strata of air surrounding the summit and the opening 
of the crater, the walls of the cone of cinders are sometimes 
in a state of glowing heat, when the whole mountain presents 
an appearance of the most fearful and portentous blackness. 
The crater, which, with very few exceptions, occupies the 
summit of the volcano, forms a deep, caldron-like valley, which 
is often accessible, and whose bottom is subject to constant al- 
terations. The great or lesser depth of the crater is in many 
volcanoes likewise a sign of the near or distant occurrence of 
an eruption. Long, narrow fissures, from which vapors issue 
forth, or small rounding hollows filled with molten masses, al- 
ternately open and close in the caldron-like valley ; the bottom 
rises and sinks, eminences of scoriae and cones of eruption are 
formed, rising sometimes far over the walls of the crater, and 
contin^jing for years together to impart to the volcano a pecul- 
iar character, and then suddenly fall together and disappear 
during a new eruption. The openings of these cones of erup- 
tion, which rise from the bottom of the crater, must not, as is 
too often done, be confounded with the crater which incloses 
them. If this be maccessible from extreme depth and from 
the perpendicular descent, as in the case of the volcano of 
Rucu Pichincha, wdiich is 15,920 feet in height, the traveler 
may look from the edge on the summit of the mountains which 
rise in the sulphurous atmosphere of the valley at his feet ; 
and I have never beheld a grander or more remarkable picture 
than that presented by this volcano. In the interval between 
two eruptions, a crater may either present no luminous ap- 
pearance, showing merely open fissures and ascending vapors, 
or the scarcely heated soil may be covered by eminences of 
scoria?, that admit of being approached without danger, and 
thus present to the geologist the spectacle of the eruption of 
burning and fused masses, which fall back on the ledge of the 
cone of scoria3, and whose appearance is regularly announced 
by small wholly local earthquakes. Lava sometimes streams 
forth from the open fissures and small hollows, without break- 
ing through or escaping beyond the sides of the crater. If, 
however, it does break through, the newly-opened terrestrial 
stream generally flows in such a quiet and well-defined course, 
that the deep valley, which we term the crater, remains acces- 



232 COSMOS. 

sible even during periods of eruption. It is impossible, with- 
out an exact representation of the configuration — the normal 
type, as it were, of fire-emitting mountains, to form a just idea 
of those phenomena which, owing to fantastic descriptions and 
an undefined phraseology, have long been comprised under the 
head of craters, cones of eriqotioii, and volcanoes. The mar- 
ginal ledges of craters vary much less than one would be led 
to suppose. A comparison of Saussure's measurements with 
my own yields the remarkable result, for instance, that in the 
course of forty-nine years (from 1773 to 1822), the elevation 
of the northwestern margin of Mount Vesuvius [Rocca del 
Palo) may be considered to have remained unchanged.* 

Volcanoes which, like the chain of the Andes, lift their sum- 
mits high above the boundaries of the region of perpetual snow, 
present peculiar phenomena. The masses of snow, by their 
sudden fusion during eruptions, occasion not only the most fear- 
ful inundations and torrents of water, in which smoking scoriae 
are borne along on thick masses of" ice, but they likewise ex- 
ercise a constant action, while the volcano is in a state of per- 
fect repose, by infiltration into the fissures of the trachytie rock. 
Cavities which are either on the declivity or at the foot of the 
mountain are gradually converted into subterranean reservoirs 
of water, which communicate by numerous narrow openings 
with mountain streams, as we see exemplified in the highlands 
of Quito. The fishes of these rivulets multiply, especially in 
the obscurity of the hollows ; and when the shocks of earth- 
quakes, which precede all eruptions in the Andes, have vio- 
lently shaken the whole mass of the volcano, these subterra- 
nean caverns are suddenly opened, and water, fishes, and tufa- 
ceous mud are all ejected together. It is through this singular 
phenomenont that the inhabitants of the highlands of Quito 
became acquainted with the existence of the little cyclopia 
fishes, termed by them the prenadilla. On the night between 
the 19th and 20th of June, 1698, when the summit of Car- 
guairazo, a mountain 19,720 feet in height, fell in, leaving 
only two huge masses of rock remaining of the ledge of the 
crater, a space of nearly thirty-two square miles was over- 
flowed and devastated by streams of liquid tufa and argilla- 
ceous mud [lodazales), containing large quantities of dead fish. 

* See the ground-work of my measurements compared with those of 
Saussure and Lord Minto, in the Abhandlungen der Akademie der Wiss. 
zu Berlin for the years 1822 and 1823. 

t Pimelodes cyclopum. See Humboldt, Recueil d' Observations dt 
Zoologie et d^Anatomie Compar^e, t. i., p. 21-25. 



VOLCANOES. 233 

In like manner, the putrid fever, which raged seven years pre- 
viously in the mountain town of Ibarra, north of Quito, was 
ascribed to the ejection of fish from the volcano of Imbaburu.* 

Water and mud, which flow not from the crater itself, but 
from the hollows in the trachytic mass of the mountain, can 
not, strictly speaking, be classed among volcanic phenomena. 
They are only indirectly connected with the volcanic activity 
of the mountain, resembling, in that respect, the singular me- 
teorological process which I have designated in my earlier writ- 
ings by the term of volcanic storm. The hot stream which 
rises from the crater during the eruption, and spreads itself in 
the atmosphere, condenses into a cloud, and surrounds the col- 
umn of fire and cinders which rises to an altitude of many 
thousand feet. The sudden condensation of the vapors, and, 
as Gay-Lussac has shown, the formation of a cloud of enor- ^ 
mous extent, increase the electric tension. Forked lightning 
flashes from the column of cinders, and it is then easy to dis- 
tinguish (as at the close of the eruption of Mount Vesuvius, in 
the latter end of October, 1822) the rolling thunder of the vol- 
canic storm from the detonations in the interior of the mount- 
ain. The flashes of lightning that darted from the volcanic 
cloud of steam, as we learn from Olafsen's report, killed eleven 
horses and two men, on the eruption of the volcano of Katla- 
gia, in Iceland, on the 17th of October, 1755. 

Having thus delineated the structure and dynamic activity 
of volcanoes, it now remains tor us to throw a glance at the 
differences existing in their material products. The subterra- 
nean forces sever old combinations of matter in order to pro- 
duce new ones, and they also continue to act upon matter as 
long as it is in a state of liquefaction from heat, and capable 
of being displaced . The greater or less pressure under which 
merely softened or wholly liquid fluids are solidified, appears to 
constitute the main diflerence in the formation of Plutonic and 
volcanic rocks. The mineral mass which flows in narrow, 
elongated streams from a volcanic opening (an earth-spring), 
is called lava. Where many such currents meet and are ar- 
rested in their course, they expand in width, filling large ba- 
sins, in which they become solidified in superimposed strata. 
These few sentences describe the general character of the prod- 
ucts of volcanic activity. 

* [It would appear, as there is no doubt that these fishes proceed from 
the mountain itself, that there must be large lakes in the interior, which 
in ordinaiy seasons are out of the immediate influence of the volcanio 
action See Daubeney, op. cit., p. 488, 497.] — Tr. 



234 COSMOS. 

Rocks which are merely broken through by the volcanic ac- 
tion are often inclosed in the igneous products. Thus I have 
ibund angular fragments of feldspathic syenite imbedded in the 
black augitic lava of the volcano of .ToruUo, in Mexico ; but 
the masses of dolomite and granular limestone, which contain 
magnificent clusters of crystalline fossils (vesuvian and garnets, 
covered with mejonite, nepheline, and sodalite), are not the 
ejected products of Vesuvius, these belonging rather to very 
generally distributed formations, viz., strata of tufa, which are 
more ancient than the elevation of the Somma and of Vesu 
vius, and are probably the products of a deep-seated and con 
cealed submarine volcanic action.* We find five metals among 
the products of existing volcanoes, iron, copper, lead, arsenic, 
and selenium, discovered by Stromeyer in the crater of Volca- 
no.! The vapors that rise from the fiwtarolles cause the sub- 
limation of the chlorids of iron, copper, lead, and ammonium ; 
iron glancel and chlorid of sodium (the latter often in large 
quantities) fill the cavities of recent lava streams and the fis- 
sures of the margin of the crater. 

The mineral composition of lava differs according to the na- 
ture of the crystalline rock of which the volcano is formed, the 
height of the point where the eruption occurs, whether at the 
foot of the mountain or in the neighborhood of the crater, and 
the condition of temperature of the interior. Vitreous volcanic 
formations, obsidian, pearl-stone, and pumice, are entirely want- 
ing in some volcanoes, while in the case of otliers they only 
proceed from the crater, or, at any rate, from very considera- 
ble heights. These important and involved relations can only 
be explained by very accurate crystallographic and chemical 
investigations. My fellow-traveler in Siberia, Gustav Rose, 
and subsequently Hermann Abich, have already been able, 
by their fortunate and ingenious researches, to throw much 
light on the structural relations of the various kinds of vol- 
canic rocks. 

* Leop. vou Buch, in Poggend., Annalen, bd. xxxvii., s. 179. 

t [The litde island of Volcano is separated from Lipari by a narrow 
channel. It appears to have exhibited strong signs of volcanic activ- 
ity long before \he Christian era, and still emits gaseous exhalations. 
Stromeyer detected the presence of selenium in a mixture of sal ammo- 
niac and sulphur. Another product, supposed to be peculiar to this 
volcano, is boracic acid, wliich lines the sides of the cavities in beauti- 
ful white silky crystals. Daubeney, op. cit., p. 257.] — Tr. 

t Regarding the chemical origin of iron glance in volcanic masses, see 
Mitscherlich, in Poggend., Annalen, bd. xv., s. 630 ; and on the libera 
tion of hydrochloric acid in the crater, see Gay-Lussac, in the Annal^ 
ic Chimique el de Physique, t. xxii., p. 423. 



VOLCANOES. 235 

Tlie greater part of the ascending vapor is mere steam. 
When condensed, this ibrms springs, as in Pantellaria,=^ where 
they are used by the goatherds of the island. On the morn- 
mg of the 26th of October, 1822, a current was seen to flow 
from a lateral fissure of the crater of Vesuvius, and was long 
supposed to have been boiling water; it was, however, shown, 
by Monticelh's accurate investigations, to consist of dry ashes, 
which fell like sand, and of lava pulverized by friction. The 
ashes, which sometimes darken the air for hours and days to- 
gether, and produce great injury to the vineyards and olive 
groves by adhering to the leaves, indicate by their columnar 
ascent, impelled by vapors, the termination of every great 
earthquake. This is the magnificent phenomenon which 
Pliny the younger, in his celebrated letter to Cornelius Tacitus, 
compares, in the ca.se of Vesuvius, to the form of a lofty and 
thickly branched and foliaceous pine. That which is de- 
scribed as flames in the eruption of scoriee, and the radiance 
of the glowing red clouds that hover over the crater, can not 
be ascribed to the efi'ect of hydrogen gas in a state of combus- 
tion. They are rather reflections of light Avhich issue from 
molten masses, projected high in the air, and also reflections 
from the burning depths, M^ience the gloAving vapors ascend. 
We will not, however, attempt to decide the nature of the 
flames, which are occasionally seen now, as in the time of 
Strabo, to rise from the deep sea during the activity of littoral 
volcanoes, or shortly before the elevration of a volcanic island. 

When the questions are asked, what is it that burns in the 
volcano ? what excites the heat, fuses together earths and 
metals, and imparts to lava currents of thick layers a degree 
of heat that lasts for many years?! it is necessarily in:iplied 
that volcanoes must be connected with the existence ot sub- 
stances capable of maintaining combustion, like the beds of 
coal in subterranean fires. According to the diflerent phase* 
of chemical science, bitumen, pyrites, the moist admixture of 
finely-pulverized sulphur and iron, pyrophoric substances, and 
the metals of the alkalies and earths, have in turn been desig- 
nated as the cause of intensely active volcanic phenomena. 
The great chemist, Sir Humphrey Davy, to whom we are in- 
debted for the knowledge of the most combustible metallic 

* [Steam issues from many parts of this insular mountain, and sev- 
eral hot sj)rings gush forth from it, which form together a lake 6000 feet 
in circumference. Daubeney, op. cit.] — Tr. 

t See the beautiful ex[)eriuieuts on the cooling of masses of rock, iu 
Bischof's Wdrmtlehrc, s. :384, 443, 500-5 12. 



236 COSMOS. 

substances, has himself renounced his bold chemical hypothesis 
in his last work {Consolatio7i in Travel, and last Dai/s of a 
Philosopher) — a work which can not fail to excite in the 
reader a feeling of the deepest melancholy. The great mean 
density of the earth (5-44), when compared with the specific 
weight of potassium (0-865), of sodium (0*972), or of the 
metals of the earths (1'2), and the absence of hydrogen gas in 
the gaseous emanations from the fissures of craters, and from 
still warm streams of lava, besides many chemical considera- 
tions, stand in opposition with the earlier conjectures of Davy 
r,iid Ampere.* If hydrogen were evolved from erupted lava, 
how great must be the quantity of the gas disengaged, when, 
the seat of the volcanic activity being very low, as in the case 
of the remarkable eruption at the foot of the Skaptar Jokul in 
Iceland (from the 11th of June to the 3d of August, 1783, 
described by Mackenzie and Soemund Magnussen), a space of 
many square miles was covered by streams of lava, accumu- 
lated to the thickness of several hundred feet I Similar diffi- 
cLilties are opposed to the assumption of the penetration of the 
atmospheric air into the crater, or, as it is figuratively ex- 
pressed, the inhalation of the earth, when we have regard to 
the small quantity of nitrogen emitted. So general, deep- 
seated, and far-propagated an activity as that of volcanoes, 
can not assuredly have its source in chemical affinity, or in 
the mere contact of individual or merely locally distributed 
substances. Modern geognosyt rather seeks the cause of this 
activity in the increased temperature with the increase of 
depth at all degrees of latitude, in that powerful internal heat 
which our planet owes to its first solidification, its formation 
in the regions of space, and to the spherical contraction of 

* See Berzelius antlWohler, in Poirgend.. Annaleji, bd. i., s. 221, and 
bJ. xi., s. 146; Gay-Lussac, in the Annates de Ckimie, t. x., xii., p. 422 ; 
and Bischof s Reasons against the Chemical Theory of Volcanoes, iu the 
Eaglisji edition of liis Wdrmelehre, p. 297-309. 

t [On the various theoi'ies that have been advanced iu explanation of 
volcanic action, see Daubeney On Volcanoes, a woi'k to which we have 
made continual reference during the preceding pages, as it constitutes 
the most recent and perfect compendium of all the important facts re- 
lating to this subject, and is peculiarly adapted to serve as a source of 
reference to the Cosmos, since the learned author in many instances en- 
ters into a full exposition of the views advanced by Baron Humboldt. 
The appendix contains several valuable notes with reference to the 
most recent works that have appeared on the Continent, on subjects re- 
lating to volcanoes ; among others, an interesting notice of Professor 
Bischof's views " on the origin of the carbonic acid discharged from 
volcanoes," as enounced in his recently published work, Lehrbuch der 
Chemischen und Physikalischen Oeologie.'\ — Tr. 



VOLCANOES. 237 

matter revolving elliptically in a gaseous condition. We have 
thus mere conjecture and supposition side by side with cer- 
tain knowledge. A philosophical study of nature strives ever 
to elevate itself above the narrow requirements of mere natural 
description, and does not consist, as we have already remark- 
ed, in the mere accumulation of isolated facts. The inquir- 
ing and active spirit of man must be suffered to pass from the 
present to the past, to conjecture all that can not yet be knov^nti 
with certainty, and still to dwell with pleasure on the ancient 
myths of geognosy which are presented to us under so many 
various forms. If we consider volcanoes as irregular inter- 
mittent springs, emitting a fluid mixture of oxydized metals, 
alkalies, and earths, flowing gently and calmy wherever they 
find a passage, or being upheaved by the powerful expansive 
force of vapors, we are involuntarily led to remember the geog- 
nostic visions of Plato, according to which hot springs, as well 
as all volcanic igneous streams, were eruptions that might be 
traced back to one generally distributed subterranean cause, 
Pyriphlegetho7i . * 

'^ According to Plato's geognostic views, as developed in the Pkcedo, 
Pyriphlegelhon plays much the same part in relation to the activity of 
volcanoes that we now ascribe to the augmentation of heat as we de- 
scend from the earth's surface, and to the fused condition of its internal 
strata. {Pheedo, ed. Ast, p. 603 and 607; Annot., p. 808 and 817.) 
"Within the earth, and all around it, are larger and smaller caverns. 
Water flows there in abundance ; also much tire and large streams of 
fire, and streams of moist mud (some purer and others more filthy), 
like those in Sicily, consisting of mud and fire, preceding the great erup- 
tion. These streams fill all places that fall in the way of their course. 
Pyriphlegethon flows forth into an extensive district burning with a 
fierce fire, v^diere it forms a lake larger than our sea, boiling with water 
and mud. From thence it moves in circles round the earth, turbid and 
muddy." This stream of molten earth and mud is so much the general 
cause of volcanic phenomena, that Plato expressly adds, "thus is Pyri- 
phlegethon constituted, from which also the streams of fire (ot (ivaaeg), 
wherever they reach the earth {oTzri av TVX(->cn- ttjc yijg), inflate such 
parts (detached fragments)." Volcanic scoriae and lava streams are 
therefore portions of Pyriphlegethon itself, portions of the subterranean 
molten and ever-undulating mass. That ol ^vaKEC are lava streams, and 
not, as Schneider, Passow, and Schleiermacher will have it, " fire-vom- 
iting mountains," is clear enough from many passages, some of which 
have been collected by Ukert {Geogr. der Griechen und Romer, th. ii., 
s. 200) ; pva^ is the volcanic phenomenon in reference to its most strik- 
ing characteristic, the lava stream. Hence the expression, the (yvaaeg 
of iE.tna. Aristot., Mirab. Ausc, t. ii., p. 833 ; sect. 38, Bekker ; 
Thucyd., iii., 116; Theophrast., De Lap., 22, p. 427, Schneider; Diod., 
v., 6, and xiv., 59, where are the remarkable words, '' Many places 
near the sea, in the neighborhood of iEtna, were leveled to the ground, 
vmb Tov Ka7\.oviiEvov pvuKog ;" Strabo, vi., p. 269 ; xiii., p. 268, and 



238 COSMOS. 

The difiererit volcanoes over the earth's surface, when they 
are considered independently of all climatic differences, are 
acutely and characteristically classified as central and linear 
volcanoes. Under the first name are comprised those which 
constitute the central point of many active mouth's of erup- 
tion, distributed almost regularly in all directions ; under the 
second, those lying at some little distance from one another, 
forming, as it were, chimneys or vents along an extended 
fissure. Linear volcanoes again admit of further subdivision, 
namely, those which rise like separate conical islands from the 
bottom of the sea, being generally parallel with a chain of 
primitive mountains, Mdiose foot they appear to indicate, and 
those volcanic chains which are elevated on the highest ridges 
of these mountain chains, of which they form the summits.* 
The Peak of Teneriffe, for instance, is a central volcano, being 
the central point of the volcanic group to which the eruption 
of Palma and Lancerote may be referred. The long, rampart- 
like chain of the Andes, which is sometimes single, and some- 
times divided into two or three parallel branches, connected 
by various transverse ridges, presents, from the south of Chili 
to the northwest coast of America, one of the grandest in- 
stances of a continental volcanic chain. The proximity of 

where there is a notice of the celebrated burning mud of the Lelantine 
plains, in Euboea, i., p. 58, Casaub. ; and Appian, De Bello Civili, v., 
114. The blame which Aristotle throws on the geognostical fantasies 
of the Phmdo {Meteor., ii., 2, 19) is especially applied to the sources of 
the rivers flowing over the earth's surface. The distinct statement of 
Plato, that " in Sicily eniptions of wet mud precede the glowing (lava) 
stream," is very remarkable. Observations on iEtna could not have led 
to such a statement, unless pumice and ashes, formed into a mud-like 
mass by admixture with melted snow and water, during the volcano- 
electric storm in the crater of eruption, were mistaken for ejected mud. 
It is more probable that Plato's streams of moist mud {vypov nrjXov 
TTorauoL) originated in a faint recollection of the salses (mud volcanoes) 
of Agrigentum, which, as I have already mentioned, eject argillaceous 
mud w^ith a loud noise. It is much to be regretted, in reference to this 
subject, that the work of Theophrastus Tvepi pvaKoq tov ev ^iKcTita, On 
the Volcanic Stream in Sicily, to which Diog. Laert., v., 49, refers, has 
not come down to us. 

* Leopold von Buch, Physikal. Beschreib. der Canarischen Inseln, s. 
326-407. I doubt if we can agree with the ingenious Charles Darwic 
{Geological Observations on Volcanic Islands, 1844, p. 127) in regard- 
ing central volcanoes in general as volcanic chains of small extent on 
})arallel fissures. Friedrich Hoffman believes that in the group of the 
Lipari Islands, which he has so admirably described, and in which two 
eruption fissures intersect near Panaria, he has found an intermediate 
link between the two principal modes in which volcanoes appear, 
namely, the central volcanoes and volcanic chains of Von Buch (Pog 
gendorf, Annalen der Physik, bd. xxvi., s. 81-88). 



VOLCANOES. 239 

active volcanoes is always manifested in the chain of the An- 
des by the appearance of certain rocks (as dolerite, melaphyre, 
trachyte, andesite, and dioritic porphyry), which divide the so- 
called primitive rocks, the transition slates and sandstones, and 
the stratified formations. The constant recurrence of this 
phenomenon convinced me long since that these sporadic rocks 
were the seat of volcanic phenomena, and were connected with 
volcanic eruptions. At the foot of the grand Tunguragua, 
near Penipe, on the banks of the Rio Puela, I first distinctly 
observed mica slate resting on granite, broken through by a 
volcanic rock. 

In the volcanic chain of the New Continent, the separate 
volcanoes are occasionally, when near together, in mutual de- 
pendence upon one another ; and it is even seen that the vol- 
canic activity for centuries together has moved on in one and 
the same direction, as, for instance, from north to south in the 
province of Quito.* The focus of the volcanic action lies be- 
low the whole of the highlands of this province ; the only 
channels of communication with the atmosphere are, howev 
er, those mountains which we designate by special names, as 
the mountains of Pichincha, Cotopaxi, and Tunguragua, and 
which, from their grouping, elevation, and form, constitute the 
grandest and most picturesque spectacle to be found in any 
volcanic district of an equally limited extent. Experience 
shows us, in many instances, that the extremities of such 
groups of volcanic chains are connected together by subterra- 
nean communications ; and this fact reminds us of the ancient 
and true expression made use of by Seneca,! that the igneous 
mountain is only the issue of the more deeply-seated volcanic 
forces. In the Mexican highlands a mutual dependence is 

* Humboldt, Geognost. Beobach, fiber die Vulkane des Hoclilandes von 
Quito, ill Poggend., Annul, der Physik, bd. xliv., s. 194. 

t Seneca, while he speaks veiy clearly regarding the problematical 
sinking of iEtna, says in his 79th letter, " Though this might happen, 
not because the mountain's height is lowered, but because the fires are 
weakened, and do not blaze out with their former vehemence ; and for 
which reason it is that such vast clouds of smoke ai'e not seen in the 
day-time. Yet neither of these seem incredible, for the mountain may 
possibly be consumed by being daily devoured, and the fire not be so 
large as formerly, since it is not self-generated here, but is kindled in 
the distant bowels of the earth, and there rages, being fed with con- 
tinual fuel, not with that of the mountain, through whicla it only makes 
its passage." The subterrauean communication, "by galleries," be- 
tween the volcanoes of Sicily, Lipari, Pithecusa (Tschia), and Vesuvius, 
"of the last of which we may conjecture that it formerly burned and 
presented a fiery circle," seems fully understood by Strabo (lib. i., p. 
247 and 248). He terms the whole district " sub-igneous." 



240 COSMOS, 

also observed to exist among the volcanic mountains Oriza- 
ba, Popocatepetl, Jorullo, and Colima ; and I have shown* 
that they all lie in one direction between 18° 59' and 19° 12' 
north latitude, and are situated in a transverse fissure running 
from sea to sea. The volcano of Jorullo broke forth on the 
29th of September, 1759, exactly in this direction, and over 
the same transverse fissure, being elevated to a height of 1 604 
feet above the level of the surrounding plain. The mountain 
only once emitted an eruption of lava, in the same manner as 
is recorded of Mount Epomeo in Ischia, in the year 1302 
But although Jorullo, vt^hich is eighty miles from any active 
volcano, is in the strict sense of the word a new mountain, it 
must not be compared vrith Monte Nuovo, near Puzzuolo, 
which first appeared on the 19th of September, 1538, and is 
rather to be classed among craters of elevation. I believe 
that I have furnished a more natural explanation of the erup- 
tion of the Mexican volcano, in comparing its appearance to 
the elevation of the Hill of Methone, now Methana, in the 
peninsula of Troezene. The description given by Strabo and 
Pausanias of this elevation, led one of the Roman poets, most 
celebrated for his richness of fancy, to develop views which 
agree in a remarkable manner with the theory of modern 
geognosy. " Near Troezene is a tumulus, steep and devoid of 
trees, once a plain, now a mountain. The vapors inclosed in 
dark caverns in vain seek a passage by which they may escape. 
The heaving earth, inflated by the force of the compressed 
vapors, expands like a bladder filled with air, or like a goat- 
skin. The ground has remained thus inflated, and the high 
projecting eminence has been solidified by time into a naked 
rock." Thus picturesquely, and, as analogous phenomena 
justify us in beUeving, thus truly has Ovid described that 
great natural phenomenon which occurred 282 years before 
our era, and, consequently, 45 years before the volcanic sepa- 
ration of Thera (Santorino) and Therasia, between Troezene 
and Epidaurus, on the same spot where Russegger has found 
veins of trachyte.f 

* Humboldt, Essai Politique sur la Now. Espagne, t. ii., p. 173-175. 
t Ovid's description of the eruptioa of Methone (Meiam., xv., p. 296 
306) : 

" Near Troezene stands a hill, exposed in air 

To winter winds, of leafy shadows bare : 

This once was level ground ; but (strange to tell) 

Th' included vapors, that in caverns dwell, 

Laboring with colic pangs, and close confined, 

In vain sought issue for the rumbhng wind : 

Yet still they heaved for vent, and heaving still, 

Enlarged the concave and shot up the hill, 



VOLCANOES. 241 

Santorino is the most important of all the islands of erup 
timt belonging to volcanic chains.* " It combines within it 



As breath extends a bladder, or the skins 
Of goats are blown t' inclose the hoarded wines ; 
The mountain yet retains a mountain's face, 
And gathered rubbish heads the hollow space." 

Dryden's Translation, 

This description of a dome-shaped elevation on the continent is of 
^reat importance in a geognostical point of view, and coincides to a re- 
markable degree with Aristotle's account {Meteor., ii., 8, 17-19) of the 
upheaval of islands of eruption : " The heaving of the earth does not 
cease till the wind (uvsfj.og) which occasions the shocks has made its 
escape into the crust of the earth. It is not long ago since this actually 
happened at Heraclea in Pontus, and a similar event formerly occurred 
at Hiera, one of the iEolian Islands. A portion of the earth swelled up. 
and with loud noise rose into the form of a hill, till the mighty urging 
blast (TTvevfia) found an outlet, and ejected sparks and ashes which 
covered the neighborhood of Lipari, and even extended to several 
Italian cities." In this descx-iption, the vesicular distension of the 
earth's crust (a stage at which many trachytic mountains have remained) 
is very well distinguished from the eruption itself. Strabo, lib. i., p. 
59 (Casaubon), likewise describes the phenomenon as it occniTed at 
Methone : near the town, in the Bay of Hermione, there arose a flaming 
eruption; a fiery mountain, seven (?) stadia in height, was then thrown 
up, which daring the day was inaccessible from its heat and sulphure- 
ous stench, but at night evolved an agreeable odor (?), and was so hot 
that the sea boiled for a distance of five stadia, and was turbid for full 
twenty stadia, and also was filled with detached masses of rock. Re- 
gai'ding the present miueralogical character of the peninsula of Methaua, 
see Fiedler, Reise durck Griechcn/and, th. i., s. 257-263. 

* [I am indebted to the kindness of Professor E. Forbes for the fol- 
lowing interesting account of the island of Santorino, and the adjacent 
islands of Neokaimeni and Microkaimeui. '' The aspect of the bay is 
that of a great crater filled with water, Thei-a and Therasia forming its 
walls, and the other islands being after-productions in its center. We 
sounded with 250 fathoms of line in the middle of the bay, between 
Therasia and the main islands, but got no bottom. Both these islands 
appear to be similarly formed of successive strata of volcanic ashes, 
which, being of the most vivid and variegated colors, present a striking 
contrast to the black and ciudery aspect of the central isles. Neokai- 
meni, the last-formed island, is a great heap of obsidian and scoriae. 
So, also, is the greater mass, Microkaimeni, which rises up in a conical 
form, and has a cavity or crater. On one side of this island, however, 
a section is exposed, and clifis of fine pumiceous ash appear stratified 
in the greater islands. In the main island, the volcanic strata abut 
against the limestone mass of Mount St. Elias in such a way as to lead 
to the inference that they were deposited in a sea bottom in which the 
present mountain rose as a submarine mass of rock. The people at 
Santorino assured us that subterranean noises are not unfrequently 
heard, especially during calms and south winds, when they say the 
water of parts of the bay becomes the color of sulphur. My own im- 
pression IS, that this group of islands constitutes a crater of elevation, 
of which the outer ones are the remains of the walls, while the central 
gi-oup are of later origin, and consist partly of upheaved sea bottom? 

Vol. I.— L 



24"2 COSMOS. 

self the history of all islands of elevation. For upward of 
2000 years, as far as history and tiadition certify, it would 
appear as if nature were striving to form a volcano in the 
midst of the crater of elevation."* Similar insular eleva- 
tions, and almost always at regular intervals of 80 or 90 
years,! have been manifested in the island of St. Michael, in 
the Azores ; but in this case the bottom of the sea has not 
been elevated at exactly the same parts. $ The island which 
Captain Tillard named Sabrina, appeared unfortunately at 
a time (the 30th of January, 1811) when the political rela- 
tions of the maritime nations of Western Europe prevented 
that attention being bestowed upon the subject by scientific 
institutions wdiich was afterward directed to the sudden ap- 
pearance (the 2d of July, 1831), and the speedy destruction of 
the igneous island of Ferdinandea in the Sicilian Sea, between 
the limestone shores of Sciacca and the purely volcanic island 
of Pantellaria.§ 

aud partly of erupted matter — erupted, liowever, beneath the surface 
of the water."] — Tr. 

^•Leop. von Buch, Physik. Beschr. der Canar. Inseln, s. 356-358, 
and particularly tlie French ti'anslation of this excellent \vork, p. 402 ; 
and his memoir in Poggendorf s Annalen, bd. xxxviii., s. 183. A sub- 
marine island has quite recently made its appearance within the crater 
of Santorino. In 1810 it was still fifteen fatlioms below the surface of 
the sea, but in 1830 it had risen to within three or four. It rises steeply 
like a great cone, from the bottom of the sea, and the continuous ac 
tivity of the submarine crater is obvious from the circumstance that sul 
phurous acid vapors are mixed with the sea water, in the eastern bay 
of Neokaimeni, in the same manner as at Vromolimni, near Methana. 
Coppered ships lie at anchor in the bay in order to get their bottoms 
cleaned and polished by this natural (volcanic) process. (Virlet, in the 
Bulletin de la Soci6t6 Giologiqnc de France, t. iii., p. 109, and Fiedler. 
Reise ditrch Griechenland, th. ii., s. 469 and 584.) 

t Appaarance of a new island near St. Miguel, one of the Azores, 11th 
of June, 1638, 31st of December, 1719, 13th of June, 1811. 

X [My esteemed finend, Dr. Webster, professor of Chemistry and 
Mineralogy at Harvard College, Cambridge, Massachusetts, U. S., in 
his Description of the Island of St. Michael, SfC, Boston, 1822, gives an 
interesting account of the sudden appearance of the island named Sa- 
brina, which was about a inile in circumference, and two or three 
hundred feet above the level of the ocean. After continuing for some 
weeks, it sank into the sea. Dr. Webster describes the whole of the 
island of St. Michael as volcanic, and containing a number of conical 
hills of trachyte, several of which have craters, and appear at some 
former time to have been the openings of volcanoes. The hot spi-ings 
which abound in the island are impregnated with sulphureted hydro- 
gen and carbonic acid gases, appearing to attest tlje existence of vol- 
canic action.] — Tr. 

§ Pi-evost, in the Bulletin de la Societe Giologique, t. iii.. j>. 04 ; Fried. 
rich H-'-ft'inati, Hlnierlassp.n>^ M^ptke. bd. ii.. >. 4'^l-4ifi. 



VOLCANOES. 24.3 

The geographical distribution of the volcanoes which have 
been in a state of activity during historical times, the great 
number of insular and littoral volcanic mountains, and the oc- 
casional, although ephemeral, eruptions in the bottom of the 
sea, early led to the belief that volcanic activity was connect- 
ed with the neighborhood of the sea, and was dependent upon 
it for its continuance. " For many hundred years," says Jus- 
tinian, or rather Trogus Pompeius, whom he follows,* " ^tna 
and the ^olian Islands have been burning, and how could 
this have continued so long if the fire had not been fed by the 

■ * " Accedunt viciiii et perpetiii iEtnae niontis ignes et insularura 
./Eoliduin, vekiti ipsis undis alatnr iiicendium ; neque euim aliter durare 
tot seculis tantus ignis potuisset, nisi humoris uutrimentis aleretur." 
(Justin, Hist. Philipp., iv., i.) The volcanic theory with which the 
physical description of Sicily here begins is extremely intricate. Deep 
strata of sulphur and resin ; a very thin soil full of cavities and easily 
fissured ; violent motion of the w^aves of the sea, which, as they strike 
together, draw down the air (the wind) for the maintenance of the fire : 
such are the elements of the theory of Trogus. Since he seems from 
Pliny (xi., 52) to have been a physiognomist, \ve may presume that his 
numerous lost works were not confined to history alone. The opinion 
that air is forced into the interior of the earth, there to act on the vol- 
canic furnaces, was connected by the ancients ^vith the supposed influ- 
ence of winds from different quarters on the intensity of the "fires burn- 
ing in iEtna, Hiera, and Stromboli. (See the remarkable passage in 
Strabo, lib. vi., p. 275 and 276.) The mountain island of Stromboli 
(Strongyle) was regarded, therefore, as the dwelling-place of ^olus, 
"the i-egulator of the winds," in consequence of the sailors foretelling 
the weather from the activity of the volcanic eruptions of this island. 
The connection between the eruption of a small volcano with the state 
of the barometer and the direction of the wind is still generally recog- 
nized (Leop. von Buch, Descr. Phys. des lies Canaries, p. 334 ; Hoff- 
mann, in Poggend., Annalen, bd. xxvi., s. viii.), although our present 
knowledge of volcanic phenomena, and the slight changes of atmos- 
pheric pressure accompanying our winds, do not enable us to offer any 
satisfactoiy explanation of the fact. Benibo, who during his youth was 
brought up in Sicily by Greek refugees, gave an agreeable narrative of 
his wanderings, and in his j^tiia Dialogus (written in the middle of 
the sixteenth century) advances the theory of the penetration of sea 
water to the very center of the volcanic action, and of the necessity of 
the proximity of the sea to active volcanoes. In ascending iEtna the 
following question was proposed : " Explana potius nobis quie petimus, 
ea incendia unde oriantur et orta quomodo perdurent. In omni tellure 
nuspiara majores fistulas aut meatus ampliores sunt quam in locis, quae 
vel mari vicina sunt, vel a man protinus alluuntur : mare erodi^ ilia 
facillime pergitque in viscera terras. Itaque cum in aliena regna sibi 
viam faciat, ventis etiam facit ; ex quo fit, ut loca qua^que maritima 
maxime terrae motibus subjecta sint, parum mediterranea. Habes 
quum in sulfuris venas venti furentes inciderint, unde incendia oriantur 
iEtnffi tUce. Vides, quse mare in radicibus habeat, qu.e sulfurea sit, 
quae cavernosa, qua? a mari aliquando perforata ventos admiserit restu- 
antes, per quos idonea flamm:e materies incenderetur." 



244 COSMOS. 

neighboring sea ?"* In order to explain the necessity of the 
vicinity of the sea, recourse has been had, even in modern 
times, to the hypothesis of the penetration of sea water into 
the foci of volcanic agency, that is to say, into deep-seated 
terrestrial strata. When I collect together all the facts that 
may be derived from my own observation and the laborious 
researches of others, it appears to me that every thing in this 
involved investigation depends upon the questions whether the 
great quantity of aqueous vapors, which are unquestionably 
exhaled from volcanoes even when in a state of -rest, be de- 
rived from sea water impregnated with salt, or rather, perhaps, 
with fresh meteoric water ; or whether the expansive force of 
the vapors (which, at a depth of nearly 94,000 feet, is equal 
to 2800 atmospheres) would be able at different depths to 
counterbalance the hydrostatic pressure of the sea, and thus 
afford them, under certain conditions, a free access to the 
focus ;t or whether the formation of metallic chlorids, the 
presence of chlorid of sodium in the fissures of the crater, and 
the frequent mixture of hydrochloric acid with the aqueous 
vapors, necessarily imply access of sea water ; or, finally, 
whether the repose of volcanoes (either when temporary, or 
permanent and complete) depends upon the closure of the 
channels by which the sea or meteoric water was conveyed, 
or whether the absence of flames and of exhalations of hydrogen 
(and sulphureted hydrogen gas seems more characteristic of 
solfataras than of active volcanoes) is not directly at variance 

* [Although extinct volcanoes seem by no means confined to the 
neighborhood of the present seas, being often scattered over the most 
inland portions of our existing continents, yet it will appear that-, at the 
time at which tliey were in an active state, the greater part were in the 
neighborhood either of the sea, or of the extensive salt or fresh water 
lakes, which existed at that period over much of what is now dry land. 
This may be seen either by refemng to Dr. Boue's map of Europe, or 
to that published by Mr. Lyell in the recent edition of his Principles of 
Geology/ (1847), from both of which it will become apparent that, at a 
comparatively recent epoch, those parts of France, of Germany, of 
Hungary, and of Italy, which afford evidences of volcanic action now 
extinct, were covered by the ocean. Daubeney On Volcanoes, p. 605.] 
— Tr. 

t Compare Gay-Lussac, Sur les Volcans, in the Annales de Chimie, 
t. xxii., p. 427, and Bischof, Wdrmelehre, s. 272. The eruptions of 
smoke and steam which have at different periods been seen in Lance 
rote, Iceland, and the Kurile Islands, during the ei-uption of the neigh 
boring volcanoes, afford indications of the I'eaction of volcanic foci 
through tense columns of water ; that is to say, these phenomena oc 
cur when the expansive force of the vapor exceeds the hydrostatic 
pressure. 



VOLCANOES. 245 

with the hypothesis of the decomposition of great masses of 
water ?* 

The discussion of these important physical questions does 
not come within the scope of a work of this nature ; but, while 
we are considering these phenomena, we would enter somewhat 
more into the question of the geographical distribution of still 
active volcanoes. We find, for instance, that in the New World, 
three, viz., Jorullo, Popocatepetl, and the volcano of De la 
Fragua, are situated at the respective distances of 80, 132, 
and 196 miles from the sea-coast, while in Central Asia, as 
Abel Remusatf first made known to geognosists, the Thian- 
schan (Celestial Mountains), in which are situated the lava- 
emitting mountain of Pe-schan, the solfatara of Urumtsi, and 
the still active igneous mountain (Ho-tscheu) of Turfan, lie at 
an almost equal distance (1480 to 1528 miles) from the shores 
of the Polar Sea and those of the Indian Ocean. Pe-schan is 
also fully 1360 miles distant from the Caspian Sea,$ and 172 
and 218 miles from the seas of Issikul and Balkasch. It is 
a fact worthy of notice, that among the four great parallel 
mountain chains which traverse the Asiatic continent from 
east to west, the Altai, the Thianschan, the Kuen-lun, and 
the Himalaya, it is not the latter chain, which is nearest to 
the ocean, but the two inner ranges, the Thianschan and the 
Kuen-lun, at the distance of 1600 and 720 miles from the sea, 
which have fire-emitting mountains like JEtna, and Vesuvius, 
and generate ammonia like the volcano of Guatimala. Chi- 
nese writers undoubtedly speak of lava streams v/hen they de- 
scribe the emissions of smoke and flame, which, issuing from 
Pe-schan, devastated a space measuring ten li^ in the first 
and seventh centuries of our era. Burning masses of stone 
flowed, according to their description, " like thin melted fat." 
The facts that have been enumerated, and to which sufficient 
attention has not been bestowed, render it probable that the 
vicinity of the sea, and the penetration of sea water to the foci 
of volcanoes, are not absolutely necessary to the eruption of 

* [See Daubeney On Volcanoes, Part iii., ch. xxxvi., xxxviii., xxxix.] 
— Tr. 

t Abel Remusat, Lettre a M. Cordier, in the Annales de Chimie, t. w. 
p. 137. 

t Humboldt, Asie Centrale, t. ii., p. 30-33, 38-52, 70-80, and 42G-428. 
The existence of active volcanoes in Kordofan, 540 miles iVoni the Red 
Sea, has been recently contradicted by Rtippell, Reisen in Nubien, 1829, 
«. 151. 

$ [A li is a Chinese measurement, equal to ab;:ut one thirtieth of a 
mile.]— Tr. 



246 COSMOS. 

subterranean fire, and that littoral situations only favor the 
eruption by forming the margin of a deep sea basin, which, 
covered by strata of water, and lying many thousand feet lower 
than the interior continent, can offer but an inconsiderable 
degree of resistance. 

The present active volcanoes, which communicate by per- 
manent craters simultaneously with the interior of the earth 
and with the atmosphere, must have been formed at a subse- 
quent period, when the upper chalk strata and all the tertiary 
formations were already present : this is shown to be the fact 
by the trachytic and basaltic eruptions which frequently form 
the walls of the crater of elevation. Melaphyres extend to the 
middle tertiary formations, but are found already in the Jura 
limestone, where they break through the variegated sandstone.* 
We must not confound the earlier outpourings of granite, quartz- 
ose porphyry, and euphotide from temporary fissures in the old 
transition rocks with the present active volcanic craters. 

The extinction of volcanic activity is either only partial — 
in which case the subterranean fire seeks another passage of 
escape in the same mountain chain — or it is total, as in Au- 
vergne. More recent examples are recorded in historical times, 
of the total extinction of the volcano of Mosychlos,t on the 
island sacred to Hephsestos (Vulcan), whose " high wdiirling 
flames" were known to Sophocles ; and of the volcano of Me- 
dina, which, according to Burckhardt, still continued to pour 
out a stream of lava on the 2d of November, 1276. Every 
stage of volcanic activity, from its first origin to its extinction, 
is characterized by peculiar products ; first by ignited scoriae, 
streams of lava consisting of trachyte, pyroxene, and obsidian, 
and by rapilli and tufaceous ashes, accompanied by the devel- 

* Dufreuoy et Elie de Beaumont, Explication de la Carte GSologiqne 
de la France, t. i.,p. 89. 

t Sophocl., Philoct., V. 971 and 972. On the supposed epoch of the 
extinction of the Lemnian fire in the time of Alexander, compare Butt- 
mann, in the Mnseiim der AHerthumswissenschaft, bd. i., 1807, s. 295 ; 
Dureau de la Malle, in Malte-Brun, Annates des Voyages, t. ix., 1809, 
p. 5 ; Ukert, in Bertuch, Geogr. Ephemeriden, bd. xxxix., 1812, s. 361; 
Rhode, Res Lemnicce, 1829, p. 8 ; and Walter, Veher Ahnahme der Vul- 
han. Thiitigkeit in Historischen Zeiten, 1844, s. 24. The chart of Lem- 
nos, constructed by Choiseul, makes it extremely probable that the ex- 
tinct crater of Mosychlos, and the island of Chryse, the desert habitation 
of Philoctetes (Otfried Miiller, Minyer, s. 300), have been long swal- 
lowed up by the sea. Reefs and shoals, to the northeast of Lemnos, 
still indicate the spot whei-e the ^Egean Sea once possessed an active 
volcano like iF,tna, Vesuvius, Stromboli, and Volcano (in the Lipaii 
Isles). 



ROCKS. 247 

opment of large quantities of pure aqueous vapor ; subsequent- 
ly, when the volcano becomes a solfatara, by aqueous vapors 
mixed with sulphureted hydrogen and carbonic acid gases ; 
and, finally, when it is completely cooled, by exhalations of 
carbonic acid alone. There is a remarkable class of igneous 
mountains which do not eject lava, but merely devastating 
streams of hot water,* impregnated with burning sulphur and 
rocks reduced to a state of dust (as, for instance, the Galun- 
gung in Java) ; but whether these mountains present a normal 
condition, or only a certain transitory modification of the vol- 
canic process, must remain undecided until they are visited by 
geologists possessed of a knowledge of chemistry in its present 
condition. 

I have endeavored in the above remarks to furnish a gen- 
eral description of volcanoes — comprising one of the most im- 
portant sections of the history of terrestrial activity — and I 
have based my statements partly on my own observations, but 
more in their general bearin,^ on the results yielded by the la- 
bors of my old friend, Leopold von Buch, the greatest geogno- 
sist of our own age, and the first who recognized the intimate 
connection of volcanic phenomena, and their mutual depend- 
ence upon one another, considered with reference to their rela- 
tions in space. 

Volcanic action, or the reaction of the interior of a planet on 
its external crust and surface, was long regarded only as an 
isolated phenomenon, and was considered solely with respect 
to the disturbing action of the subterranean force ; and it is 
only in recent times that — greatly to the advantage of geog- 
nostical views based on physical analogies — volcanic forces 
have been regarded as forming 7iew rocks, and iranforining 
those that already existed. We here arrive at the point to 
which I have already alluded, at which a well-grounded study 
of the activity of volcanoes, whether igneous or merely such 
as emit gaseous exhalations, leads us, on the one hand, to the 
mineralogical branch of geognosy (the science of the texture 
and the succession of terrestrial strata), and, on the other, to 
the science of geographical forms and outlines — the configura- 
tion of continents and insular groups elevated above the level 

* Compare Reiuwardt and Hoflfmauu, iu Poggendorf 's Annalen, bd. 
xii., s. 607 ; Leop. von Buch, Descr. des lies Canaries, p. 424-426. Tiie 
eruptions of argillaceous mud at Carguairazo, when that volcano was 
destroyed iu 1698, the Lodazales of Igualata, and the Moya of Pelileo 
—all on the table-land of Quit^ — arc volcanic phenomena of a similar 
nature. 



248 COSMOS. 

of the sea. This extended insight into the cc^ action of nat 
ural phenomena is the result of the philosop lical direction 
which has been so generally assumed by the more earnest 
study of geognosy. Increased cultivation of science and en- 
largement of political views alike tend to unite elements that 
had long been divided. 

If, instead of classifying rocks according to their varieties of 
form and superposition into stratified and unstratified, schistose 
and compact, normal and abnormal, v/e investigate those phe- 
nomena of formation and transformation which are still going 
on before our eyes, we shall find that rgcks admit of being ar- 
ranged according to four modes of origin. 

Rocks of eruption, which have issued from the interior of 
the earth either in a state of fusion from volcanic action, or 
in a more or less soft, viscous condition, from Plutonic action. 

Sedimentary rocks, which have been precipitated and de- 
posited on the earth's surface from a fluid, in which the most 
minute particles were either dissolved or held in suspension 
constituting the greater part of the secondary (or flotz) and 
tertiary groups. 

Transformed or raetamorphic rocks* in which the internal 
texture and the mode of stratification have been changed, ei- 

* [As the doctriue of mineral metamurphism is nov/ eJccitiug veiy 
general attention, we subjoin a few explanatory observations by the 
celebrated Swiss philosopher. Professor Stoder, taken from the Edinh. 
New Philos. Journ., Jan., 1848: "In its widest sense, mineral meta- 
morphism means every change of aggregation, structure, or chemical 
condition which rocks have undergone subsequently to their deposition 
and stratification, or the effects which have been produced by other 
forces than gravity and cohesion. There fall under this definition, the 
discoloration of the surface of black limestone by the loss of carbon ; 
the formation of brownish-red crusts on rocks of limestone, sandstone, 
many slate stones, serpentine, granite, &c., by the decomposition of ir(ni 
pyrites, or magnetic iron, finely disseminated in the mass of the rock ; 
the conversion of anhydrite into gypsum, in consequence of the absorp- 
tion of water ; the crumbling of many granites and porphyries into 
gravel, occasioned by the decomposition of the mica and feldspar. In 
'ts more limited sense, the term metamorphic is confined to those 
changes of the rock which are produced, not by the effect of the at- 
mosphere or of water on the exposed surfaces, but which are produced, 
directly or indirectly, by agencies seated in the interior of the earth. 
In many cases the mode of change may be explained by our physical 
or chemical theories, and may be viewed as the effect of temperature 
or of electro-chemical actions. Adjoining rocks, or connecting com- 
Hiunications with the interior of the earth, also distinctly point out the 
seat from which the change proceeds. In many other cases the meta- 
morphic process itself remains a mystery, and from the nature of the 
products alone do we conclude that such a metamorphic action has 
taken place."] — Tr. 



ROCKS. 249 

ther by contact or proximity with a Plutonic or volcanic en- 
dogenous rock of eruption,* or, what is more frequently the 
case, by a gaseous sublimation of substancest which accom- 
pany certain masses erupted in a hot, fluid condition. 

Conglomerates ; coarse or finely granular sandstones, or 
breccias composed of mechanically-divided masses of the three 
previous species. 

These four modes of formation — ^by the emission of volcanic 
masses, as narrow lava streams ; by the action of these masses 
on rocks previously hardened ; by mechanical separation or 
chemical precipitation from liquids impregnated v/ith carbonic 
acid ; and, finally, by the cementation of disintegrated rocks 
of heterogeneous nature — are phenomena and formative pro- 
cesses which must merely be regarded as a faint reflection of 
that more energetic activity wliich must have characterized 
the chaotic condition of the earlier world under wholly difier- 
ent conditions of pressure and at a higher temperature, not 
only in the whole crust of the earth, but likewise in the more 

* lu a plan of the neighborhood of Tezcuco, Totouilco, and Moran 
(Atlas Giographique et Physique, pi. vii.), which I originally (1803) 
intended for a woi'k which I never published, entitled Pasigrafia Geog- 
nostica destinada al uso de los Jovenes del Colegio de Mineria de Mexi- 
co, I named (in 1832) the Plutonic and volcanic ex'uptive rocks endoge- 
nous (generated in the interior), and the sedimentary and flotz rocks 
exogenous (or generated externally on the surface of the earth). Pasi- 
graphically, the former w^ere designated by an arrow directed up- 
ward f , and the latter by the same symbol directed downward |. 
These signs have at least some advantage over the ascending lines, 
which in the older systems represent arbitrarily and ungracefully the 
horizontally ranged sedimentary strata, and their penetration through 
masses of basalt, porphyry, and syenite. The names proposed in the 
pasigraphico-geognostic plan were borrowed from De Candolle's nomen 
clature, in which endogenous is synonymous with monocotyledonous, 
and exogenotis with dicotyledonous plants. Mohl's more accurate ex- 
amination of vegetable tissues has, however, shown that the growth of 
monocotyledons from w^ithin, and dicotyledons from without, is not 
strictly and generally true for vegetable orga^iisms (Link, Elementa 
Philosophice Botanicce, t. i., 1837, p. 287; Endlicher and Unger, Grund- 
zuge der Botanik, 1843, s. 89 ; and Jussieu, TraiU de Botanique, t. i., 
p. 85). The rocks which I have termed endogenous are characteristic- 
ally distinguished by Lyell, in his Principles of Geology, 1833, vol. iii., 
p. 374, as " nether-formed" or " hypogene rocks." 

t Compare Leop. von Buch, Ueber Dolom.it als Gehirgsart, !t823, s. 
36 ; and his remarks on the degree of fluidity tp be ascribed to Plutonic 
rocks at the period of their eruption, as well as on the formation of 
gneiss from schist, through the action of granite and of the substances 
upheaved with it, to be found in the Abhandl. der Akad. der Wissen- 
»ch. zu Berlin for the year 1842, s. 58 und 63, and in the Jahrhucli fui 
Wissenschaftliche Kritik, 1840, s. 195. 

L 2 



250 COSMOS. 

extended atmosphere, overloaded with vapors. The vast fis- 
sures which were formerly open in the solid crust of the eartli 
have since been filled up or closed by the protrusion of eleva- 
ted mountain chains, or by the penetration of veins of rocks of 
eruption (granite, porphyry, basalt, and melaphyre) ; and while, 
on a superficial area equal to that of Europe, there are now 
scarcely more than four volcanoes remaining through which 
fire and stones are erupted, the thinner, more fissured, and un- 
stable crust of the earth was anciently almost every where 
covered by channels of communication between the fused in- 
terior and the external atmosphere. Gaseous emanations, ris- 
ing from very unequal depths, and therefore conveying sub- 
stances difiering in their chemical nature, imparted greater 
activity to the Plutonic processes of formation and transform- 
ation. The sedimentary formations, the deposits of liquid fluids 
from cold and hot springs, which we daily see producing the 
travertine strata near Rome, and near Hobart Town in Van 
Diemen's Land, afibrd but a faint idea of the flotz formation. 
In our seas, small banks of limestone, almost equal in hardness 
at some parts to Carrara marble,* are in the course of forma- 
tion, by gradual precipitation, accumulation, and cementation 
— processes whose mode of action has not been sufficiently 
well hivestigated. The Sicilian coast, the island of Ascension, 
and King George's Sound in Australia, are instances of this 
mode of formation. On the coasts of the Antilles, these 
formations of the present ocean contain articles of pottery, 
and other objects of human industry, and in Guadaloupe even 
human skeletons of the Carib tribes. t The negroes of the 
French colonies designate these formations by the name of 
Maconne-bo?i-Dieu.t A small oolitic bed, formed in Lan- 
cerote, one of the Canary Islands, and which, notwithstand- 

* Darwin, Volcanic Islands, 1844, p. 49 and 154. 

t [In most instances the bones are dispersed ; but a large.slab of rock, 
ui which a considerable portion of the skeleton of a female is imbedded, 
is preserved in the British Museum. The presence of these bones has 
been explained by the circumstance of a battle, and the massacre of a 
tribe of Gallibis by the Caribs, v/hich took place near the spot in which 
they are found, about 120 years ago ; for, as the bodies of the slain 
were i|^terred on the sea-shore, their skeletons may have been subse- 
quently covered by sand-drift, which has since consolidated into lime- 
stone. Dr. Moultrie, of the Medical College, Charleston, South Caro- 
liua, U. S., is, however, of opinion that these bones did not belong to 
individuals of the Carib tribe, but of the Peruvian race, or of a tribe 
possessing a similar craniological development.] — Tr. 

t Moreau de Jonnes, Hisf. Phys. des Antilles, t. i., p. 136, 138, and 
543; Humboldt, Relation Historique, X. iii., (>. 367. 



\ 



ROCKS. 251 

ino" its recent formation, bears a resemblance to Jura lime- 
stone, has been recognized as a product of the sea and of tem- 
pests.* 

Composite rocks are definite associations of certain oryctog-- 
uustic, simple mmerals, as feldspar, mica, solid silex, ausrite, 
and nepheline. Rocks very similar to these, consisting of the 
same elements, but grouped differently, are still formed by 
volcanic processes, as in the earlier periods of the world. The 
character of rocks, as we have already remarked, is so inde- 
pendent of geographical relations of space,! that the geologist 
recognizes with surprise, alike to the north or the south of 
the equator, in the remotest and most dissimilar zones, the 
familiar aspect, and the repetition of even the most minute 
characteristics in the periodic stratification of the silurian 
strata, and in the effects of contact with augitic masses o^' 
eruption. 

We will now enter more fully into the consideration of the 
four modes in which rocks are formed — the four phases ot" 
their formative processes manifested in the stratified and uu- 
stratified portions of the earth's surface ; thus, in the endog- 
enous or erupted rocks, designated by modern geognosists as 
compact and abnormal rocks, we may enumerate the follow- 
ing principal groups as immediate products of terrestrial ac- 
tivity : 

1 . Granite and syenite of very different respective ages ; 
the granite is frequently the more recent,| traversing the sy- 
enite in veins, and being, in that case, the active upheaving 
agent. " Where the granite occurs in large, insulated masses 
of a faintly-arched, ellipsoidal form, it- is covered by a crust or 
shell cleft into blocks, instances of which are met with alike 
in the Hartz district, in Mysore, and in Lower Peru. This 
sea of rocks probably owes its origin to a contraction of the 
surface of the granite, owing to the great expansion that ac- 
companied its first upheaval. "§ 

Both in Northern Asia, II on the charming and romantic 
shores of the Lake of Kolivan, on the northwest declivity of 

* Near Teguiza. Leop. von Buch, Canarische Inseln, s. 301. 

t Leop. von Buch, op. cit., p. 9. 

t Bernhard Cotta, Geognosie, 1839, 8. 273. 

§ Leop. von Buch, Ueber Granit und Gneiss, in the Abhandl. der Berl. 
Akad. for the year 1842, s. 60. 

II In the projecting mural masses of granite of Lake Kolivan, divided 
into narrow parallel beds, there are numerous crystals of feldspar and 
albite, and a few of titanium (Humboldt, Asie Centrale, t. i., p. 29.0, 
Qustav Rose. Reisc nncli dcm Ural, bd. i., s. 524). 



252 COSMOS. 

the Altai Mountains, and at Las Trincheras, on the slope ol 
the littoral chain of Caraccas,* I have seen granite divided 
into ledges, owing probably to a similar contraction, although 
the divisions appeared to penetrate far into the interior. Fur- 
ther to the south of Lake Kolivan, toward the boundaries of 
the Chinese province Hi (between Buchtarminsk and the 
River Narym), the formation of the erupted rock, in which 
there is no gneiss, is more remarkable than I ever observed in 
any other part of the earth. The granite, which is always 
covered with scales and characterized by tabular divisions, 
rises in the steppes, either in small hemispherical eminences, 
scarcely six or eight feet in height, or like basalt, in mounds, 
terminating on either side of their bases in narrow streams.! 
At the cataracts of the Orinoco, as well as in the district 
of the Fichtelgebirge (Seissen), in Galicia, and between the 
Pacific and the highlands of Mexico (on the Papagallo), I 
have seen granite in large, flattened spherical masses, which 
could be divided, like basalt, into concentric layers. In the 
valley of Irtysch, between Buchtarminsk and Ustkamenogorsk, 
granite covers transition slate for a space of four miles,! pen- 
etrating into it from above in narrow, variously ramified, 
wedge-like veins. I have only instanced these peculiarities 
in order to designate the individual character of one of the 
most generally difiused erupted rocks. As granite is super- 
posed on slate in Siberia and in the Departement de Finisterre 
(Isle de Mihau), so it covers the Jura limestone in the mount- 
ains of Oisons (Ferments), and syenite, and indirectly also 
chalk, in Saxony, near Weinbohla.§ Near Mursinsk, in the 
Uralian district, granite is of a drusous character, and here 
the pores, like the fissures and cavities of recent volcanic prod- 
ucts, inclose many kinds of magnificent crystals, especially 
beryls and topazes. 

2. Quartzose porphyry is often found in the relation of 
veins to other rocks. The base is generally a finely granular 
mixture of the same elements which occur in the larger im- 

* Humboldt, Relation Historique, t. ii., p. 99. 

t See the sketch of Bu-i-tau, which I took from the south side, where 
the Kirghis tents stood, and which is given in Rose's Reise, bd. i., s. 584. 
On spheres of granite scaling off concentrically, see my Relat. Hist., t. 
ii-, p. 497, and Essai Giogn. sur les Gisement des Roches, p. 78. 

X Humboldt, Asie Centrale, t. i., p. 299-311, and the di-awings in 
Rose's i2ee«e, bd. i., s. 611, in which we see the curvature in the layers 
of granite which Leop. von Buch has pointed out as characteristic. 

§ This remarkable superposition was first described by Weiss in 
Karsten's Archiv fur Bergbau mid Huttemcesen, bd. xvi., 1827, s. 5. 



ROCKS. 253 

bedded crystals. In granitic porphyry that is very poor in 
quartz, the feldspathic base is ahnost granular and laminated.* 

3. Greenstones, Diorite, are granular mixtures oi' white 
albite and blackish-green hornblende, forming dioritic porphy- 
ry when the crystals are deposited in a base of denser tissue. 
The greenstones, either pure, or inclosing laminae of diallage 
(as in the Fichtelgebirge), and passing into serpentine, have 
sometimes penetrated, in the form of strata, into the old strat- 
ified fissures of green argillaceous slate, but they more fre- 
quently traverse the rocks in veins, or appear as globular 
masses of greenstone, similar to domes of basalt and porphyry. t 

Hij'persthene rock is a granular mixture of labradorite and 
hypersthene. 

Euphotide and serpentine, containing sometimes crystals 
of augite and uralite instead of diallage, are thus nearly allied 
to another more frequent, and, I might almost say, more en 
ergetic eruptive rock — augitic porphyry. $ 

Melaphyre, augitic, uralitic, and oligoklastic porphyries 
To the last-named species belongs the genuine verd-antique^ 
so celebrated in the arts. 

Basalt, containing olivine and constituents which gelatin- 
ize in acids ; phonolithe (porphyritic slate), trachyte, and dol- 
erite ; the fi.rst of these rocks is only partially, and the second 
always, divided into thin laminee, which give them an ap- 
pearance of stratification when extended over a large space. 
Mesotype and nepheline constitute, according to Girard, an 
important part in the composition and internal texture of ba- 
salt. The nepheline contained in basalt reminds the geog- 
nosist both of the miascite of the Ilmen Mountains in the 
TJral,§ which has been confounded with granite, and some- 
times contains zirconium, and of the pyroxenic nepheline dis- 
covered by Gumprecht near Lobau and Chemnitz. 

To the second or sedimentary rocks belong the greater part 
of the formations which have been comprised under the old 

* Dufrenoy et Elie de Beaumont, Giologie de la France, t. i., p. 130. 

t These intercalated beds of diorite play an important part in the 
mountain district of Nailau, near Steben, where I was engaged in 
mining operations in the last century, and with which the happiest as- 
sociations of my early life are connected. Compare Hoffmann, in Pog- 
gendorf 's Annalen, bd. xvi., s. 558. 

X In the southern and Bashkirian portion of the Ural. Rose, Reise, 
bd. ii., s. 171. 

$ G. Rose, Reise nach dem Ural, bd. ii., s. 47-52. Respecting the 
identity of eleolite and nepheline (the latter containing rather the more 
lime), see Scheerer, in Poggend., Annalen, bd. xlix., s. 359-381. 



254 COSMOS 

Bysteniatic, but not very correct designation of transition, Jl'utz 
or secondary, and tertiary formations. If the erupted rocks 
had not exercised an elevating, and, owing to the simultane- 
ous shock of the earth, a disturbing influence on these sedi- 
mentary formations, the surface of our planet would have 
consisted of strata arranged in a uniformly horizontal direc- 
tion above one another. Deprived of mountain chains, on 
whose declivities the gradations of vegetable forms and the 
scale of the diminishing heat of the atmosphere appear to be 
picturesquely reflected — furrowed only here and there by val- 
leys of erosion, formed by the force of fresh water moving on 
in gentle undulations, or by the accumulation of detritus, re- 
sulting from the action of currents of water — continents would 
have presented no other appearance from pole to pole than 
the dreary uniformity of the llanos of South America or the 
steppes of Northern Asia. The vault of heaven would every 
where have appeared to rest on vast plains, and the stars to 
rise as if they emerged from the depths of ocean. Such a 
condition of things could not, however, have generally pre- 
vailed for any length of time in the earlier periods of the 
world, since subterranean forces must have striven in all ep- 
ochs to exert a counteracting influence. 

Sedimentary strata have been either precipitated or depos- 
ited from liquids, according as the materials entering into 
their composition are supposed, whether as limestone or ar- 
gillaceous slate, to be either chemically dissolved or suspend- 
ed and commingled. But earths, when dissolved in fluids 
impregnated with carbonic acid, must be regarded as under- 
going a mechanical process while they are being precipitated, 
deposited, and accumulated into strata. This viev/ is of some 
importance with respect to the envelopment of organic bodies 
in petrifying calcareous beds. The most ancient sediments 
of the transition and secondary formations have probably been 
formed from water at a more or less high temperature, and 
at a time when the heat of the upper surface of the earth 
was still very considerable. Considered in this point of view, 
a Plutonic action seems to a certain extent also to have taken 
place in the sedimentary strata, especially the more ancient ; 
but these strata appear to have been hardened into a schistose 
structure, and under great pressure, and not to have been 
solidified by cooling, like the rocks that have issued from the 
interior, as, for instance, granite, porphyry, and basalt. By 
degrees, as the waters lost their temperature, and were able 
to absorb a copious supply of the carbonic acid gas with w^hich 



ROCKS. 255 

the atmosphere was overcharged, they became fitted to hold 
m solution a larger quantity ol' lime. 

Tlte sedimentary strata, setting aside all other exogenous, 
purely mechanical deposits of sand or detritus, are as follows : 

ScJiist, of the lower and upper transition rock, composing 
the Silurian and devonian formations ; from the lower silurian 
strata, which were once termed cambrian, to the upper strata 
of the old red sandstone or devonian formation, immediately 
in contact with the mountain limestone. 

Carboniferous deposits : 

Limestones imbedded in the transition and carboniferous 
formations ; zechstein, muschelkalk. Jura formation and chalk, 
also that portion of the tertiary formation which is not includ- 
ed in sandstone and conglomerate. 

Travertine, fresh-water limestone, and silicious concretions 
of hot springs, formations which have not been produced un- 
der the pressure of a large body of sea water, but almost in 
immediate contact with the atmosphere, as in shallow marsh- 
es and streams. 

Infusorial dejjosits : geognostical phenomena, whose great 
importance in proving the influence of organic activity in the 
formation of the solid part of the earth's crust was first dis- 
covered at a recent period by my highly-gifted friend and fel- 
low-traveler, Ehrenberg. 

If, in this short and superficial view of the mineral con- 
stituents of the earth's crust, I do not place immediately after 
the simple sedimentary rocks the conglomerates and sandstone 
formations which have also been deposited as sedimentary 
strata from liquids, and which have been imbedded alternate- 
ly with schist and limestone, it is only because they contain, 
together with the detritus of eruptive and sedimentary rocks, 
also the detritus of gneiss, mica slate, and other metamorphic 
masses. The obscure process of this metamorphism, and the 
action it produces, must therefore compose the third class of 
the fundamental forms of rock. 

Endogenous or erupted rocks (granite, porphyry, and mela- 
phyre) produce, as I have already frequently remarked, not 
only dynamical, shaking, upheaving actions, either vertically 
or laterally displacing the strata, but they also occasion chang- 
es in their chemical composition as well as in the nature of 
their internal structure ; new rocks being thus formed, as 
gneiss, mica slate, and granular limestone (Carrara and Pa- 
rian marble). The old silurian or devonian transition schists, 
the belemnitic limestone of Tarantaise, and the dull gray cal 



256 COSMOS. 

careous sandstone (Macig7io), which contains algsB found in 
the northern Apennines, often assume a new and more brill- 
iant appearance after their metamorphosis, which renders il 
difficult to recognize them. The theory of metamorphism 
was not established until the individual phases of the change 
were followed step by step, and direct chemical experimenta 
on the difference in the fusion point, in the pressure and time 
of cooling, were brought in aid of mere inductive conclusions. 
Where the study of chemical combinations is regulated by 
leading ideas,* it may be the means of throwing a clear light 
on the wide field of geognosy, and over the vast laboratory of 
nature in which rocks are continually being formed and mod- 
ified by the agency of subterranean forces. The philosophical 
inquirer will escape the deception of apparent analogies, and 
the danger of being led astray by a narrow view of natural 
phenomena, if he constantly bear in view the complicated 
conditions which may, by the intensity of their force, have 
modified the counteracting effect of those individual substan 
ces whose nature is better known to us. Simple bodies have, 
no doubt, at all periods, obeyed the same laws of attraction, 
and, wherever apparent contradictions present themselves, T 
am confident that chemistry will in most cases be able to 
trace the cause to some corresponding error in the experiment. 
Observations made with extreme accuracy over large tracts 
of land, show that erupted rocks have not been produced in an 
irregular and unsystematic manner. In parts of the globe most 
remote from one another, we often find that granite, basalt, and 
diorite have exercised a regular arid uniform metamorphic ac- 
tion, even in the minutest details, on the strata of arjjillaceous 
slate, dense limestone, and the grains of quartz in sandstones. 
As the same endogenous rock manifests almost every where the 
same degree of activity, so, on the contrary, different rocks be- 
longing to the same class, whether to the endogoiious or the 
erupted, exhibit great differences in their character. Intense 
heat has undoubtedly influenced all these phenomena, but the 
degree of fluidity (the more or less perfect mobility of the parti- 
cles — their more viscous composition) has varied very consid- 
erably from the granite to the basalt, while at different geo- 

* See the admirable researches of Mitscherlich, in the Ahhandl. dei 
Berl. Akad. for the years 1822 and 1823, s. 25-41 ; and in Poggend., 
Annalm, bd. x., s. 137-152; bd. xi., a. 323-332; bd. xli., s. 21^3-21^ 
(Gustav Rose, Ueher Bildung des Kalkspaths U7id Aragonits, iu Pog- 
gend , Annalen, bd. xli., s, 353-366 ; Huidinger, in the Transactions 
tfthe Royal Society of Edinburgh, 1827, p. 148.) 



ROCKS. 257 

iogical periods (or metamorphic phases of the earth's crust) 
other substances dissolved in vapors have issued from the in- 
terior of the earth simultaneously with the eruption of granite, 
basalt, greenstone porphyry, and serpentine. This seems a 
fitting place again to draw attention to the fact that, accord- 
ing to the admirable views of modern geognosy, the meta- 
morphism of rocks is not a mere phenomenon of contact, limit- 
ed to the effect produced by the apposition of two rocks, since 
it comprehends all the generic phenomena that have accom- 
panied the appearance of a particular ei^pted mass. Even 
where there is no immediate contact, the proximity of such a 
mass gives rise to modifications of solidification, cohesion, gran- 
ulation, and crystallization. 

All eruptive rocks penetrate, as ramifying veins, either into 
the sedimentary strata, or into other equally endogenous mass- 
es ; but there is a special importance to be attached to the 
difference manifested between Plutonic rocks* (granite, por- 
ph}Ty, and serpentine) and those termed volcanic in the strict 
sense of the word (as trachyte, basalt, and lava). The rocks 
produced by the activity of our present volcanoes appear as 
band-like streams, but by the confluence of several of them 
they may form an extended basin. Wherever it has been 
possible to trace basaltic eruptions, they have generally been 
found to terminate in slender threads. Examples of these 
narrow openings may be found in three places in Germany : 
in the " Pjlaster-kaute,'' at Marksuhl, eight miles from Ei- 
senach ; in the blue " Kuppe,'' near Eschwege, on the banks 
of the Werra ; and in the Druidical stone on the Hollert road 
(Siegen), where the basalt has broken through the variegated 
sandstone and gray wacke slate, and has spread itself into cup- 
like fungoid enlargements, which are either grouped together 
like rows of columns, or are sometimes stratified in thin 1am- 
inse. The case is otherwise with granite, syenite, quartzose 
porphyry, serpentine, and the whole series of unstratified com- 
pact rocks, to which, from a predilection for a mythological 
nomenclature, the term Plutonic has been applied. These, 
with the exception of occasional veins, were probably not 
erupted in a state of fusion, but merely in a softened condi- 
tion ; not from narrow fissures, but from long and widely-ex- 
tending gorges. They have been protruded, but have not 
flowed forth, and are found, not in streams like lava, but in 
extended masses.! Some groups of dolerite and trachyte in- 

* [Lyell, Principles of Geology, vol. i.i., p. 353 aud 359.] — Tr 

t The desciiptiou here given of the relations of position under which 



'^58 COSMOS. 

dicate a certain degree of basaltic fluidity ; others, which iiavu 
been expanded into vast craterless domes, appear to have been 
only in a softened condition at the time of their elevation. 
Other trachytes, like those of the Andes, in which I have fre- 
quently perceived a striking analogy with the greenstones and 
syenitic porphyries (which are argentiferous, and without 
quartz), are deposited in the same manner as granite and 
quartzose porphyry. 

Experiments on the changes which the texture and chem- 
ical constitution of rocks experience from the action of heat, 
have shown that volcanic masses* (diorite, augitic porphyry, 
basalt, and the lava of ^tna) yield different products, accord- 
ing to the difference of the pressure under which they have 
been fused, and the length of time occupied during their cool- 
ing ; thus, where the cooling was rapid, they form a black 
glass, having a homogeneous fracture, and where the cooling 
was slow, a stony mass of granular crystalline structure. In 
the latter case, the crystals are formed partly in cavities and 
partly inclosed in the matrix. The same materials yield the 
most dissimilar products, a fact that is of the greatest import- 
ance in reference to the study of the nature of erupted rocks, and 
of the metamorphic action which they occasion. Carbonate of 
lime, when fused under great pressure, does not lose its carbonic 
acid, but becomes, when cooled, granular limestone ; when 
the crystallization has been effected by the dry method, sac- 
charoidal marble ; while by the humid method, calcareous 
spar and aragonite are produced, the former under a lesser de- 
gree of temperature than the latter. f Differences of temper- 
granite occurs, expresses the geiieral or leading character of the whole 
fonnatiou. But its aspect at some places leads to the belief that it was 
occasionally more fluid at the period of its eruption. The description 
given by Rose, in his Reise nach dem Ural, bd. i., s. 599, of part of the 
Narym chain, near the frontiers of the Chinese territories, as well as the 
evidence afforded by trachyte, as described by Dufrenoy and Elie de 
Beaumont, in their Description Giologique de la France, t. i., p. 70. 
Having already spoken in the text of the narrow apertures through 
which the basalts have sometimes been effused, I will here notice the 
large fissures, which have acted as conducting passages for melaphyres, 
which must not be confounded with basalts. See Murchison's inter- 
esting account ( The Silurian System, p. 126) of a fissure 480 feet wide, 
through which melaphyre has been ejected, at the coal-mine at Corn- 
brook, Hoar Edge. 

* Sir James Hall, in the Edin. Trans., vol. v., p. 43, and vol. vi., p. 
71; Gregory Watt, in the Phil. Trans, of the Roy. Soc. of London for 
1804, Part ii., p. 279 ; Dartigues and Fleurieu de Bellevue, in the Jour- 
nal de Physique, t. Ix,, p. 456; Biscliof, Wurmelchre, s. 313 und 443. 

t Gustav R.)se, in ]';)u';-'-ij(l., Aannl'-n, Ik! xlii., i" 3o4, 



ROCKS. 259 

ftxure likewise modify the direction in which the diilerent par- 
ticles arrange themselves in the act of crj'staliization, and also 
atlect the form of the crystal.* Even when a body is not in 
a fluid condition, the smallest particles may undergo certain 
relations in their various modes of arrangement, which are 
manifested by the different action on light. t The phenome- 
na presented by devitrification, and by the formation of steel 
by cementation and casting — the transition of the fibrous into 
the granular tissue of the iron, from the action of heat,$ and 
probably, also, by regular and long-continued concussions — 
likewise throw a considerable deo-ree of lisfht on the gfcolooical 
process of metamorphism. Heat may even simultaneously in- 
duce opposite actions in crystalline bodies ; for the admirable 
experiments of Mitscherlich have established the facts^ that 
calcareous spar, without altering its condition of aggregation, 
expands in the direction of one of its axes and contracts in 
the other. 

If we pass from these general considerations to individual 
examples, we find that schist is converted, by the vicinity of 
Plutonic erupted rocks, into a bluish-black, glistening roofing 
slate. Here the planes of stratification are intersected by an- 
other system of divisional stratification, almost at right ano'les 
with the former, ii and thus indicating an action subsequent to 
the alteration. The penetration of silica causes the argilla- 
ceous schist to be traversed by quartz, transforming it, in part, 
into whetstone and silicious schist ; the latter sometimes con- 
taining carbon, and being then capable of producing galvanic 
effects on the nerves. The highest degree of silicification of 
schist is that observed in ribbon jasper, a material highly val- 
uable in the arts, If and which is produced in the Ourai Mount- 

* On the dimorphism of sulphur, see Mitscherhch, Lehrhuch der 
Chemie, $ 55-G3. 

t On gypsum as a uniaxal crystal, and on the sulphate of magnesia, 
and the oxyds of zinc and nickel, see Mitscherlich, in Poggend.. Anna- 
len, bd. xi., s. 328. 

X Coste, Versuche am Creusot uber das hruchig werden des Staheisens. 
Elie de Beaumont, Mem. Geol., t. ii., p. 411. 

§ Mitscherlich, Ueber die Ausdehniing der Krystallisirten Kurper durch 
die Wdrmelehre, in Poggend., Annalen, bd. x., s. 151. 

II On the double system of divisional planes, see Elie de Beauniijut, 
Geologic de la France, p. 41 ; Credner, Geognosie Thuringens und dcs 
Harzes, s. 40; and Ronier, Das Rheinische Uehergangsgebirge. 1844, 
s. 5 nnd 9. 

^ The t;ilica is not merely colored by peroxyd of iron, but is accom- 
panied by clay, lime, and potash. Ro.-^e, Rcise, bd. ii.. s. 187. On llie 
lormalion of jasper by llic acti.Mi wf dioriiic porphyry, angilo, and hy 



260 COSMOS. 

ains by the contact and eruption of augitic porphyry (at Orsk), 
of dioritic porphyry (at Aufschkul), or of a mass of hyper- 
sthenic rock conglomerated into spherical masses (at Bogos- 
lowsk). At Monte Serrato, in the island of Elba, according 
to Frederic Hoffman, and in Tuscany, according to Alexander 
Brongniart, it is formed by contact with euphotide and ser- 
pentine. 

The contact and Plutonic action of granite have sometimes 
made argillaceous schist granular, as was observed by Gustav 
Rose and myself in the Altai Mountains (within the fortress 
of Buchtarminsk),^ and have transformed it into a mass re- 
sembling granite, consisting of a mixture of feldspar and mica, 
in which larger laminae of the latter were again imbedded. ■'■ 
Most geognosists adhere, with Leopold von Buch, to the well- 
known hypothesis " that all the gneiss in the silnrian strata of 
the transition formation, between the Icy Sea and the Gulf of 
Finland, has been produced by the metamorphic action of 
granite.! In the Alps, at St. Gothard, calcareous marl is 
likewise changed from granite into mica slate, and then trans- 
formed into gneiss." Similar phenomena of the formation of 
gneiss and mica slate through granite present themselves in 
the oolitic group of the Tarantaise,§ in which belemnites are 

perslliene rock, see Rose, bd. ii., s. IG9, 187, uud 192. See, also, bd. 
i., s. 427, where there is a drawing of the porphyry spheres between 
which jasper occurs, in the calcareous graywacke of Bogoslowsk, being 
prodaced by the Plutonic influence of the augitic rock; bd. ii., s. 54-5; 
and likewise Humboldt, Asie Centrale, t. i., p. 486. 

* Rose, Reise nacli dem Ural, bd. i., s. 580-588. 

t In respect to the volcanic origin of mica, it is important to notice 
that ciystals of mica are found in the basalt of the Bohemian Mittelge- 
birge, in the lava that in 1822 was ejected from Vesuvius (Monticelli, 
Storia del Vesuvio negli Anni 1821 e 1822, § 99), and in fragments of 
argillaceous slate imbedded in scoriaceous basalt at Hohenfels, not far 
from Gerolstein, in the Eifel (see Mitscherlich, in Leonhard, Basali- 
Gehilde, s. 244). On the formation of feldspar in argillaceous schist, 
through contact with porphyiy, occurring between Urval and Poi'et 
(Forez), see Dufreuoy, in 6*1^0^. de la France, t. i., p. 137. It is proba- 
bly to a similar contact that certain schists near Paimpol, in Brittany, 
with vi'hose appearance I was much struck, while making a geological 
pedestrian tour through that interesting country with Professor Kunth, 
owe their amygdaloid and cellular character, t. i., p. 234. 

X Leopold von Buch, in the Abhandlungen der Akad. der Wissen- 
schaft zu Berlin, aus dem JaJir 1842, s. 63, and in the JahrMichern fur 
Wissenschaftliche Krilik Jahrg. 1840, s. 196. 

$ Elie de Bea^lmont, in the Annales des Sciences Naiurelles, t. xv., p. 
362-372. " In approaching the primitive masses of Mont Rosa, and the 
mountains situated to the west of Coni, we pei'ceive that the secondary 
Btrata gradually lose the characters inherent in their mode of deposition. 
Frequently assuming a character apparently arising from a perfectly 



ROCKS. 201 

found in rocks, which have some claim to be considered as 
mica slate, and in the schistose group in the western part of 
the island of Elba, near the promontory of Calamita, and the 
Fichtelgebirge in Baireuth, between Lomitz and Markleiten.* 
Jasper, which,! as I have already remarked, is a production 
formed by the volcanic action of augitic porphyry, could only 
be obtained in small quantities by the ancients, while another 
material, very generally and efficiently used by them in the 
arts, was granular or saccharoidal marble, which is likewise 
to be regarded solely as a sedimentary stratum altered by ter- 
restrial heat and by proximity with erupted rocks. This opin- 
ion is corroborated by the accurate observations on the phe- 
nomena of contact, by the remarkable experiments on fusion 

distinct cause, but not losing their stratification, tliey somewhat resem- 
ble in their physical structure a biaud of half-consumed wood, in which 
we can follow the traces of the ligneous fibers beyond the spots which 
continue to present the natural characters of wood." (See, also, the 
Annates des Sciences Naturclles, t. xiv., p. 118-122, and von Dechen, 
Geognosie, s. 553.) Among the most striking proofs of the transforma- 
tion of rocks by Plutonic action, we must place the belemnites in the 
Bchists of Nufibnen (in the Alpine valley of Eginen and in the Gries- 
glaciers), ani^the belemnites found by M. Charpentier in the so-called 
primitive limestone on the western descent of the Col de la Seigne, be- 
tween the Enclove de Monjovet and the chdlet of La Lanchette, and 
which he showed to me at Bex in the autumn of 1822 {Annales de 
Chimie, t. xxiii., p. 262). 

* Hoffmann, in Poggend., AnnaJen, bd. xvi., s. 552, " Strata of tran 
sition argillaceous schist in the Fichtelgebirge, which can be traced for 
a length of 16 miles, are transformed into gneiss only at the two ex- 
tremities, where they come in contact with granite. We can there 
follow the gradual formation of the gneiss, and the development of the 
mica and of the feldspathic amygdaloids, in the interior of the argilla- 
ceous schist, which indeed contains in itself almost all the elements of 
these substances." 

t Among the works of art which have come down to us from the an 
cient Greeks and Romans, we observe that none of any size — as columns 
or large vases — are formed from jasper; and even at the present day, 
this substance, in large masses, is only obtained from the Ural Mountains. 
The material worked as jasper from the Rhubarb Mountain (Raveniaga 
Sopka), in Altai, is a beautiful ribboned poi-phyry. The word jasper 
is derived from the Semitic languages ; and from the confused descrip- 
tions of Theophrastus (De Lapidibus, 23 and 27) and PUuy (xxxvii., 8 
and 9), who rank jasper among the " opaque gems," the name appears 
to have been given to fragments of jaspachat, and to a substance which 
the ancients termed jasponyx, which we now know as opal-jasper. 
Pliny considers a piece of jasper eleven inches in length so rare as to 
require his mentioning that he had actually seen such a specimen : 
" Magnitudinem jaspidis undecim unciarum vidimus, formataiuque iude 
effigiem Neronis thoracatam." According to Theophrastus, the stone 
which he calls emerald, and from which large obelisks were cut, must 
have been an imperfect jasper. 



262 COSMOS. 

made by Sir James Hall more than half a century ago, and 
by the attentive study of granitic veins, which has contributed 
so largely to the establishment of modern geognosy. Some- 
times the erupted rock has not transformed the compact into 
granular limestone to any great depth from the point of con- 
tact. Thus, for instance, we meet with a slight transforma- 
tion — a penumbra — as at Belfast, in Ireland, where the ba* 
saltic veins traverse the chalk, and, as in the compact cal- 
careous beds, which have been partially inflected by the con- 
tact of syenitic granite, at the Bridge of Boscampo and the 
Cascade of Conzocoli, in the Tyrol (rendered celebrated by 
the mention made of it by Count Mazari Pcucati).* Another 
mode of transformation occurs where all the strata of the com- 
pact limestone have been changed into granular hmestone by 
the action of granite, and syenitic or dioritic porphyry. f 

I would here wish to make special mention of Parian and 
Carrara marbles, which have acquired such, celebrity from the 
noble works of art into which they have been converted, and 
which have too long been considered in our geognostic collec- 
tions as the main types of primitive limestone. The action 
of granite has been manifested sometimes by immediate con- 
tact, as in the Pyrenees,^ and sometimes, as in the main land 
of Greece, and in the insular groups in the ^Egean Sea, through 
the intermediate layers of gneiss or mica slate. Both cases 
presuppose a simultaneous but heterogeneous process of trans 

* Humboldt, Leitre a M. Brochant de Villiers, in the Annales dc 
Chimie et de Physique, t. xxiii., p. 261 ; Leop. voii Buch, Geog. Brief e 
iiber das sudliche Tyrol, s. 101, 105, iind 273. 

t On the transformation of compact into granular limestone by the 
action of granite, in the Pyrenees at the Montagnes de Rancie, see 
Dufrenoy, in the M^moires Gdologiques, t. ii., p. 440 ; and on similai 
changes in the Montagues de VOisans, see Elie de Beaumont, in ihe 
Mem. G6olog., t. ii., p. 379-415; on a similar effect produced by the 
action of dioritic and pyroxenic porphyry (the ophite described by Elie 
de Beaumont, in the G6ologie de la France, t. i., p. 72), between Tulosa 
and St. Sebastian, see Dufrenoy, in ihe M6m. Giolog., t. ii., p. 130; and 
by syenite in the Isle of Skye, where the fossils in the altered limesloue 
may still be distinguished, see Von Dechen, in his G6ognosie, p. 573. 
In the transformation of chalk by contact with basalt, the transposition 
of the most minute particles in the processes of crystallization and 
granulation is the more remarkable, because the excellent microscopic 
investigations of Ehrenberg have shown that the particles of chalk pre- 
viously existed in the form of closed rings. See Poggend., Annalen der 
Physik, bd. xxxix., s. 105; and on the rings of aragonite deposiled 
from solution, see Gustav Rose in vol. xlii., p. 354, of the same journal. 

X Beds of granular limestone in the granite at Port d'Oo and in the 
Mont de Labourd. See Charpentier, Constittition Geologiqve des PyrA- 
nies, p. 144, ] 46. 



KOCKS. 263 

formation. In Attica, in the island of Eubcea, and in the 
Peloponnesus, it has been remarked, " that the limestone, 
when superposed on mica slate, is beautiful and crystalline in 
proportion to the purity of the latter substance and to the 
smallness of its argillaceous contents ; and, as is well known, 
this rock, together with beds of gneiss, appears at many points, 
at a considerable depth below the surface, in the islands of 
Paros and Antiparos."* We may here infer the existence of 
an imperfectly metamorphosed flotz formation, if faith can be 
yielded to the testimony of Origen, according to whom, the 
ancient Eleatic, Xenophanes of Colophont (who supposed the 
whole earth's crust to have been once covered by the sea), de- 
clared that marine fossils had been found in the quarries of 
Syracuse, and the impression of a fish (a sardine) in the deepest 
rocks of Paros. The Carrara or Luna marble quarries, which 
constituted the principal source from which statuary marble 
was derived even prior to the time of Augustus, and which 
will probably continue to do so until the quarries of Paros 
shall be reopened, are beds of calcareous sandstone — macigno 
— altered by Plutonic action, and occurring in the insulated 
mountain of Apuana, between gneiss-like mica and talcose 
schist. I Whether at some points granular limestone may 
not have been formed in the interior of the earth, and been 
raised by gneiss and syenite to the surface, where it forms 
vein-like fissures, § is a question on which I can not hazard 
an opinion, owing to my own want of personal knowledge of 
the subject. 

* Leop. vou Biich, Descr. des Canaries, p. 394 ; Fiedler, Raise durch 
das Konigreich Griechenland, tb. ii., s., 181, 190, und 516, 

t I have previously alluded to the remarkable passage in Origen's 
Philosophumena, cap. 14 {Opera, ed. Delarue, t. i., p. 893). From the 
whole context, it seems very improbable that Xenophanes meant an 
impression of a laurel {tvkov (Ju^vff) instead of an impression of a fish 
{tvtzov u.(pVT]g). Delame is wrong in blaming the correction of Jacob 
Gronovius in changing the laurel into a sardel. Tlie petrifaction of a 
fish is also much more probable than the natural picture of Silenus, 
which, accoi'ding to Phny (lib. xxxvi., 5), the quarry-men are stated to 
have met with in Parian marble from Mount Marpessos. Servius ad 
Virg., ^n., \i.. All. 

X On the geoguostic relations of Carrara ( The City of the Moon, Strabo, 
lib. v., p. 222), see Savi, Osservazioni sui terreni antichi Toscani, in 
the Nnovo Giornale de' Letterati di Pisa, and Hoffmann, in Karsten's 
Archiv far Mineralogie, bd. vi., s. 2.58-263, as well as in his Geogn. 
Reise durch Italien, s. 244-265. 

^ According to the assumption of an excellent and very experienced 
observer, Karl von Leonhard. See his Jahrbuch fiir Mineralogie, 1834 
e. 329, aud Bernhard Cotta, Geognosie, s. 310. 



264 COSMOS. 

According to the admirable observations of Leopold von 
Buch, the masses of dolomite fomid in Southern Tyrol, and on 
the Italian side of the Alps, present the most remarkable in- 
stance of metamorphism produced by massive eruptive rocks 
on compact calcareous beds. This formation of the hmestone 
seems to have proceeded from the fissures which traverse it in 
all directions. The cavities are every v/here covered w^ith 
rhomboidal crj'^stals of magnesian bitter spar, and the v^hole 
formation, without any trace of stratification, or of the fossil 
remains which it once contained, consists only of a granular 
aggregation of crystals of dolomite. Talc laminse lie scattered 
here and there in the newly-formed rock, traversed by masses 
of serpentine. In the valley of the Fassa, dolomite rises per- 
pendicularly in smooth walls of dazzling whiteness to a height 
of many thousand feet. It forms sharply -pointed conical 
mountains, clustered together in large numbers, but yet not in 
contact with each other. The contour of their forms recalls to 
mind the beautiful landscape with which the rich imagination 
of Leonardi da Vinci has embellished the back-ground of the 
portrait of Mona Lisa. 

The geognostic phenomena which we are now describing, 
and which excite the imagination as well as the powers of the 
intellect, are the result of the action of augitic porphyry man- 
ifested in its elevating, destroying, and transforming force.* 
The process by which limestone is converted into dolomite is 
not regarded by the illustrious investigator who first drew at- 
tention to the phenomenon as the consequence of the talc being 
derived from the black porphyry, but rather as a transforma- 
tion simultaneous with the appearance of this erupted stone 
through wide fissures filled with vapors. It remains for future 
inquirers to determine how transformation can have been effect- 
ed without contact with the endogenous stone, where strata 
of dolomite are found to be interspersed in limestone. Where, 
in this case, are we to seek the concealed channels by which 
the Plutonic action is conveyed ? Even here it may not, how- 
ever, be necessary, in conformity with the old Roman adage, 
to believe " that much that is alike in nature may have been 
formed in wholly difierent ways." When we find, over widely- 
extended parts of the earth, that two phenomena are always 
associated together, as, for instance, the occurrence of mela- 

* Leop. von Buch, Geognostische Briefe an Alex, von Humboldt, 1824, 
«. 86 and 82 ; also in the Annalen de Ckemie, t. xxiii., p. 276, and in the 
Ahhandl. der Berliner Akad. avs der Jahren 1822 i(?id 1823, s. 83-136 ; 
Von Dechen, Geognosie, s. 574-576. 



ROCKS. 265 

phyre and the transformation of compact lii^iestone into a crys- 
talline mass differing in its chemical character, we are, to a 
certain degree, justified in believing, where the second phe- 
nomenon is manifested unattended by the appearance of the 
first, that this apparent contradiction is owing to the absence, 
in certain cases, of some of the conditions attendant upon the 
exciting causes. Who would call in question the volcanic na- 
ture and igneous fluidity of basalt merely because there are 
some rare instances in which basaltic veins, traversing beds 
of coal or strata of sandstone and chalk, have not materially 
deprived the coal of its carbon, nor broken and slacked the 
sandstone, nor converted the chalk into granular marble 1 
Wherever we have obtained even a faint light to guide us in 
the obscure domain of mineral formation, we ought not un- 
gratefully to disregard it, because there may be much that is 
still unexplained in the history of the relations of the transi- 
tions, or in the isolated interposition of beds of unaltered strata. 

After having spoken of the alteration of compact carbonate 
of lime into granular limestone and dolomite, it still remains 
for us to mention a third mode of transformation of the same 
mineral, which is ascribed to the emission, in the ancient pe- 
riods of the world, of the vapors of sulphuric acid. This trans- 
formation of limestone into gypsum is analogous to the pene- 
tration of rock salt and sulphur, the latter being deposited 
from sulphureted aqueous vapor. In the lofty Cordilleras of 
Quindiu, far from all volcanoes, I have observed deposits of 
sulphur in fissures in gneiss, while in Sicily (at Cattolica, near 
Girgenti), sulphur, gypsum, and rock salt belong to the most 
recent secondary strata, the chalk formations.*" I have also 
seen, on the edge of the crater of Vesuvius, fissures filled with 
rock salt, which occurred in such considerable masses as occa- 
sionally to lead to its being disposed of by contraband trade. 
On both declivities of the Pyrenees, the connection of diorit? 
and pyroxene, and dolomite, gypsum, and rock salt, can not be 
questioned ;t and here, as in the other phenomena which we 
have been considering, every thing bears evidence of the ac- 
tion of subterranean forces on the sedimentary strata of the 
ancient sea. 

There is much difficulty in explaining the origin of the beds 
of pure quartz, which occur in such large quantities in South 
America, and impart so peculiar a character to the chain of 

* Hoffmau, Geogn. Reise, edited by Von Declieu, s. 113-119, and 
380-386; Poggend., Annalen der Physik, bd. xxvi., s. 41. 

t DiifVenoy, in the Memoires Geologiqnes. t. ii.. p. 145 and 179. 
Vol. I.— M 



266 COSMOS. 

the Andes.* In descending toward the South Sea, fiom Cax- 
amarca toward Guangamarca, I have observed vast ra,asses 
of quartz, from 7000 to 8000 feet in height, superposed some- 
times on porphyry devoid of quartz, and sometimes on dioritc. 
Can these beds have been transformed from sandstone, as 
EHe de Beaumont conjectures in the case of the quartz strata 
on the Col de La Poissonniere, east of Brian^on ?t In the 
Brazils, in the diamond district of Minas Geraes and St. Paul, 
which has recently been so accurately investigated by Clausen, 
Plutonic action has developed in dioritic veins sometimes ordi- 
nary mica, and sometimes specular iron in quartzose itacol- 
umite. The diamonds of Grammagoa are imbedded in strata 
of solid silica, and are occasionally enveloped in lamiuje of 
mica, like the garnets found in mica slate. The diamonds 
that occur furthest to the north, as those discovered in 1829 
at 58'^ lat., on the European slope of the Uralian Mountains, 
bear a geognostic relation to the black carboniferous dolomite 
of xldolfiskoit and to augitic porphyry, although more accu- 
rate observations are required in order fully to elucidate this 
subject. 

Among the most remarkable phenomena of contact, v/e 
must, finally, enumerate the formation of garnets in argilla- 
ceous schist in contact with basalt and dolerite (as in Northum- 
berland and the island of Anglesea), and the occurrence of a 
vast number of beautiful and most various crystals, as garnets, 
vesuvian, augite, and ceylanite, on the surfaces oi" contact be- 
tween the erupted and sedimentary rock, as, for instance, on 
the junction of the syenite of Monzon with dolomite and com- 
pact limestone. § In the island of Elba, masses of serpentine, 
which perhaps nowhere more clearly indicate the character of 
erupted rocks, have occasioned the sublimation of iron glance 
and red oxyd of iron in fissures of calcareous sandstone.il We 
still daily find the same iron glance formed by sublimation 
from the vapors and the walls of the fissures of open veins on 
the margin of the crater, and in the fresh lava currents of the 
volcanoes of Stromboli, Vesuvius, and -^tna.lF The veins that 

* Humboldt, Essai Oeogn. sur le Gisement des Roches, p. 93 ; Asie 
Ccntrale, t. iii., p. 532. 

t Elie de Beaumont, in the Annales des Sciences Naturelles, t. xv., ]) 
362 ; Murchison, Silurian System, p. 286. 

+ Rose, Reise nach dem Ural, bd. i., s. 364 und 367. 

<^ Leop. vou Bucb, Briefe, s. 109-129. See, also, Elie do Beaumont, 
Oil the Contact of Granite toith the Beds of the Jura, in the 31^m. GeoL, 
t. ii., }). 408. II Hoifman, Reise, a. 30 niid 37. 

11 On the chemical process iu the f<jrmatioa oi' bpeculur i:'oii, s(.n^ Guy 



ROCKS. 267 

are thus formed beneath our eyes by volcanic forces, where 
the contiguous rock has already attained a certain degree of 
solidification, show us how, in a similar manner, mineral and 
metallic veins may have been every where formed in the more 
ancient periods of the world, where the solid but thinner crust 
of our planet, shaken by earthquakes, and rent and fissured 
by the change of volume to which it was subjected in cooling, 
may have presented many communications with the interior, 
and many passages for the escape of vapors impregnated with 
earthy and metallic substances. The arrangement of the par- 
ticles in layers parallel with the margins of the veins, the regu- 
lar recurrence of analogous layers on the opposite sides of the 
veins (on their different walls), and, finally, the elongated cel- 
lular cavities in the middle, frequently afford direct evidence 
of the Plutonic process of sublimation in metalliferous veins. 
As the traversing rocks must be of more recent origin than 
the traversed, we learn from the relations of stratification ex- 
isting between the porphyry and the argentiferous ores in the 
Saxon mines (the richest and most important in Germany), 
that these formations are at any rate more recent than the 
vegetable remains found in carboniferous strata and in the red 
sandstone.* 

All the facts connected with our geological hypotheses on 
the formation of the earth's crust and the metamorphism of 
rocks have been unexpectedly elucidated by the ingenious 
idea which led to a comparison of the slags or scoriae of our 
smelting furnaces with natural minerals, and to the attempt 
of reproducing the latter from their elements.! In all these 
operations, the same affinities manifest themselves which de- 
termine chemical combinations both in our laboratories and 
in the interior of the earth. The most considerable part of 

Lussac, in the Annates de Chimie, t. xxii., p. 41.5, and Mitscherlich, in 
Poggeud., Annalen, bd. xv., s. 630. Moreover, crystals of olivine have 
been formed (probably by sublimation) in the cavities of the obsidian 
of Cerro del Jacal, whicla I brought from Mexico (Gustav Rose, in 
Poggend., Annalen, bd. x., s. 323). Hence olivine occurs in basalt, 
lava, obsidian, artificial scoria?, in meteoric stones, in the syenite of Elf- 
dale, and (as hyalosiderite) in the wacke of the Kaiserstahl. 

* Constantin von Beust, Ueber die Porphyrgebilde, 1835, s. 89-96 ; 
also his Beleuchtung der Werner^ schen Gangtheorie, 1840, s. 6 ; and C 
von Wissenbach, Ahhildungen merkwurdiger Gangverhdltnisse, 1836, fig. 
12. The ribbon-like structure of the veins is, how^ever, no more to bo 
regarded of general occurrence than the periodic order of the differen* 
members of these masses. 

t Mitscherlich. Ueber die kunstliche DarsteUnng der Mineralien, m 
the Abhandl. der Akademie der Wiss. zu Berlin, 1822-3, s. 2.5-41 



268 COSMOS. 

the simple minerals which characterize the more generally 
diffused Plutonic and erupted rocks, as well as those on which 
they have exercised a metamorphic action, have been produced 
in a crystalline state, and with perfect identity, in artificial 
mineral products. We must, however, distinguish here be- 
tween the scoriae accidentally formed, and those which have 
been designedly produced by chemists. To the former belong 
feldspar, mica, augite, olivine, hornblende, crystallized oxyd 
of iron, magnetic iron in octahedral crystals, and metallic 
titanium ;* to the latter, garnets, idocrase, rubies (equal in 
hardness to those found in the East), olivine, and augite. t 
These minerals constitute the main constituents of granite, 
gneiss, and mica schist, of basalt, dolerite, and many porphy- 
ries. The artificial production of feldspar and mica is of most 
especial geognostic importance with reference to the theory of 
the formation of gneiss by the metamorphic agency of argilla- 
ceous schist, which contains all the constituents of granite, 

* In scoriae, crystals of feldspar have been discovered by Heine in 
the refuse of a furnace for copper fusing, near Sangerhausen, and ana- 
lyzed by Kersten (Poggend., Annalcn, bd. xxxiii., s. 337); crystals of 
augite in scoriae, at Sahle (Mitscherlich, in the Abhandl. der Akad. zu 
Berlin, 1822-23, s. 40); of olivine by Seifstrom (Leonhard, Basalt-Ge- 
bilde, bd. ii., s. 495); of mica in old scoriae of Schloss Garpenberg 
(Mitscherlich, in Leonhard, op. cit., s. 506) ; of magnetic iron in the 
scoriae of Chatillon sur Seine (Leonhard, s. 441) ; and of micaceous iron 
in potter's clay (Mitscherlich, in Leonhard, op. cit., s. 234). 

[See Ebelmer's papers in Ann. de Chimie et de Physique, 1847 ; also 
Report on the Crystalline Slags, by John Percy, M.D., F.R.S., and 
William Hallows Miller, M.A., 1847. Dr. Percy, in a communication 
with which he has kindly favored me, says that the minerals which he 
has found artificially produced and proved by analysis are Humboldtil- 
ite, gehleuite, olivine, and magnetic oxyd of iron, in octahedral crys- 
tals. He suggests that the circumstance of the production of gehlenite 
at a high temperature in an iron furnace may possibly be made avail- 
able by geologists in explaining the formation of the rocks in which the 
natural mineral occurs, as in Fassathal in the Tyrol.] — Tr. 

t Of minerals purposely produced, we may mentioia idocrase and 
garnet (Mitscherlich, in Poggend., Annalen der Physik, bd. xxxii., s. 
340); ruby (Gaudin, in the Compies Rendus de VAcademie de Science, 
t. iv., Part i., p. 999) ; olivine and augite (Mitscherlich and Berthier, in 
the Annales de Chimie et de Physique, t. xxiv., p. 376). Notwithstand- 
ing the greatest possible similarity in crystalline form, and perfect iden- 
tity in chemical composition, existing, according to Gustav Rose, be- 
tween augite and hornblende, hornblende has never been found accom- 
panying augite in scoriae, nor have chemists ever succeeded in artificial- 
ly producing either hornblende or feldspar (Mitscherlich in Poggend., 
Annalen, bd. xxxiii., s. 340, and Rose, Reise nach dem Ural, bcT. ii., s. 
358 und 363). See, also, Beudant, in the Mem. de V Acad, des Sciences, 
t. viii., p. 221, and Becquerel's ingenious experiments in his Trait' <it 
I Electric'ti, t. i., p. 334 ; t. iii., p. 218; and t. v., p. 148 and 185 



ROCKS. 269 

potash not excepted.* It would not b3 very surprising, there- 
fore, as is well observed by the distinguished geognosist, Von 
Dechen, if we were to meet with a fragment of gneiss formed 
on the walls of a smelting furnace which was built of argilla- 
ceous slate and graywacke. 

' After having taken this general view of the three classes 
of erupted, sedimentary, and metamorphic rocks of the earth's 
crust, it still remains for us to consider the fourth class, com- 
prising conglomerates, or rocks of detritus. The very term 
recalls the destruction which the earth's crust has suffered, 
and likewise, perhapw, reminds u? of the process of cementation, 
which has connected together, by means of oxyd of iron, or of 
some argillaceous and calcareous substances, the sometimes 
rounded and sometimes angular portions of fragments. Con- 
glomerates and rocks of detritus, when considered in the widest 
sense of the term, manifest characters of a double origin. The 
substances which enter into their mechanical composition have 
not been alone accumulated by the action of the waves of the 
sea or currents of fresh water, for there are some of these rocks 
the formation of which can not be attributed to the action of 
water. " When basaltic islands and trachytic rocks rise on 
fissures, friction of the elevated rock against the walls of the 
fissures causes the elevated rock to be inclosed by conglom- 
erates composed of its own matter. The granules composing 
the sandstones of many formations have been separated rather 
by friction against the erupted volcanic or Platonic rock than 
destroyed by the erosive force of a neighboring sea. The ex- 
istence of these friction conglomerates, which are met with in 
enormous masses in both hemispheres, testifies the intensity 
ot" the force with which the erupted rocks have been propelled 
from the interior through the earth's crust. This detritus 
has subsequently been taken up by the waters, which have 
then deposited it in the strata which it still covers. "t Sand- 
stone formations are found imbedded in all strata, from the 
lower silurian transition stone to the beds of the tertiary form- 
ations, supei-posed on the chalk. They are found on the 
margin of the boundless plains of the New Continent, both 
within and without the tropics, extending like breast-works 
along the ancient shore, against which the sea once broke in 
foaming waves. 

* D'Aubuisson, in the Journal de Physique, t. Ixviii., p. 128. 

t Leop. von Buch, Gcognost. Briefe, s. 75-8"J. w'uere it is also showi? 
why the new red saudstoue (the Todtliegende of the Tlinringiaii flota 
formatioii) and the coal measures must be regarded as produ'-ed b^ 
erupted porpliyiy. 



270 COSMOS. 

If we cast a glance on. tlie geographical distribution of 
rocks, and their relations in space, in that portion of the earth's 
crust which is accessible to us, we shall find that the most 
universally distributed chemical substance is silicic acid, gen- 
erally in a variously-colored and opaque form. Next to solid 
silicic acid we must reckon carbonate of lime, and then the 
combinations of silicic acid with alumina, potash, and soda, 
with lime, magnesia, and oxyd of iron. 

The substances which we designate as rocks are determin- 
ate associations of a small number of minerals, in which some 
combine parasitically, as it were, with others, but only under 
definite relations ; thus, for instance, although quartz (silica), 
feldspar, and mica are the principal constituents of granite, 
these minerals also occur, either individually or collectively, 
in many other formations. By way of" illustrating how the 
quantitative relations of one feldspathic rock differ from anoth- 
er, richer in mica than the former, I would mention that, ac- 
cording to Mitscherlich, three times more alumina and one 
third more silica than that possessed by feldspar, give the con- 
stituents that enter into the compositi(5n of mica. Potash is 
contained in both — a substance whose existence in many kinds 
of rocks is probably antecedent to the dawn of vegetation on 
the earth's surface. 

The order of succession, and the relative age of the difierent 
formations, may be recognized by the superposition of the sed- 
imentary, metamorphic, and conglomerate strata ; by the na- 
ture of the formations traversed by the erupted mas.ses, and 
— with the greatest certainty — by the presence of organic re- 
mains and the diflerences of their structure. The application 
of botanical and zoological evidence to determine the relative 
age of rocks — this chronometry of the earth's surface, which 
was already present to the lofiy mind of Hooke — indicates one 
of the most glorious epochs of modern geognosy, which has 
finally, on the Continent at least, been emancipated from the 
sway of Semitic doctrines. Palseontological investigations 
have imparted a vivifying breath of grace and diversity to thb 
science of the solid structure of the earth. 

The fossiliferous strata contain, entombed within them, the 
floras and faunas of by-gone ages. We ascend the stream of 
time, as in our study of the relations of superposition we de- 
scend deeper and deeper through the different strata, in which 
lies revealed before us a past world of animal and vegetable 
life. Far-extending disturbances, the elevation of great mount- 
ain chains, whose relative ages we are able to define, attest the 



PALAEONTOLOGY. 271 

destruction of ancient and the manifestation of recent organ- 
isms. A few of these older structures have remained in the 
midst of more recent species. Owing to the hmited nature of 
our knowledge of existence, and from the figurative terms by 
which we seek to hide our ignorance, we apply the appellation 
recent structure to the historical phenomena ot" transition man- 
ifested in the organisms as well as in the forms of primitive 
seas and of elevated lands. In some cases these organized 
structures have been preserved perfect in the minutest details 
of tissues, integument, and articulated parts, while in others, 
the animal, passing over soft argillaceous mud, has left noth- 
ing but the traces of its course, =^ or the remains of its undi- 
gested food, as in the coprolites.f In the lower Jura forma- 
tiolis (the lias of Lyme Regis), the ink bag of the sepia has 
been so wonderfully preserved, that the material, which myr- 

* [III certain localities of the new red sandstone, in the Valley of the 
Connecticut, numerous tridactyl marldngs have been occasionally ob- 
served on the surface of the slabs of stone vv^hen split asunder, in like 
manner as the ripple-marks appear on the successive layers of sandstone 
in Tilgate Forest. Some remarkably distinct impressions of this kind, 
at Turner's Falls (Massachusetts), happening to attract the attention of 
Dr. James Deane, of Greenfield, that sagacious obsei'ver was struck 
with their resemblance to the foot-marks left on the mud-banks of the 
adjacent river by the aquatic birds which had recently frequented the 
spot. The specimens collected were submitted to Professor G. Hitch- 
cock, who followed up the inquiry with a zeal and success that have 
led to the most interesting results. No reasonable doubt now- exists 
that the imprints in question have been produced by the tracks of bi- 
peds impressed on the stone when in a soft state. The announcement 
of this extraordinary phenomenon was first made by Professor Hitc'i- 
cock, in the American Journal of Science (January. 1836), and that 
eminent geologist has since published full descriptions of the different 
species of imprints which he has detected, in his splendid work on the 
geology of Massachusetts. — iMantell's Medals of Creation, vol. ii., p. 810. 
In the work of Dr. Mantell above referred to, there is, in vol. ii., p. 815, 
an admirable diagram of a sbb from Turner's Falls, covered with nu- 
merous foot-marks of birds, indicating the track of ten or twelve indi- 
viduals of different sizes.] — Tr. 

t [From the examination of the fossils spoken of by geologists under 
the name of Coprolites, it is easy to determine the nature of the food of 
the animals, and some other points; and when, as happened occasion- 
ally, the animal was killed while the process of digestion was going on, 
the stomach and intestines being partly filled with half-digested I'ootl, 
and exhibiting the coprolites actually in situ, we can make out wit!i 
certainty not only the true nature of the food, but the proportionate si/e 
of the stomach, and the length and nature of the intestinal canal. With 
in the cavity of the nb of an extinct animal, the palaeontologist \{iw* 
finds recorded, in indelible characters, some of those hiei'oglyplii<-.s upon 
which he founds his hi.stoiT. — The Ancient World, by D. T. An&ted 
1817, p. 173.] — Tr. 



272 . COSMOS. 

iads of years ago might have served the animal to conceal it- 
self from its enemies, still yields the color with which its image 
may be drawn.*" In other strata, again, nothing remains bul 
the faint impression of a muscle shell ; but even this, if it be- 
long to a main division of mol}usca,t may serve to show the 
traveler, in some distant land, the nature of the rock in which 
it is found, and the organic remains with which it is associa* 
ted. Its discovery gives the history of the country in which b 
occurs. 

The analytic study of primitive animal and vegetable lift 
has taken a double direction : the one is purely morpholog- 
ical, and embraces, especially, the natural history and phys- 
iology of organisms, filling up the chasms in the series of stil) 
hving species by the fossil structures of the primitive world. 
The second is more specially geognostic, considering fossil re- 
mains in their relations to the superposition and relative age 
of the sedimentary formations. The former has long predom- 
inated over the latter, and an imperfect and superficial com- 
parison of fossil remains with existing species has led to errors, 
which may still be traced in the extraordinary names applied 
to certain natural bodies. It was sought to identify all fossil 
species with those still extant in the same manner as, in the 
sixteenth century, men were led by false analogies to com- 
pare the animals of the New Continent with those of the Old. 
'Peter Camper, Soramering, and Blumenbach had the merit 
of being the first, by the scientific application of a more ac- 

* A discovery made by Miss Mary Auniiig, who was likewise the 
discovei-er of the coprolites of fish. These coprolites, and the excre- 
ments of the Ichthyosauri, have been found in such abundance in Eu« 
gland (as, for instance, near Lyme Regis), that, according to Buckland's 
expression, they lie like potatoes scattered in the ground. See Buck- 
land, Geology considered with reference to Natural Theology, vol. i., p. 
188-202 and 305. With I'espect to the hope expressed by Hooke " to 
raise a chronology" from the mere study of broken and fossilized shells 
" and to state the interval of time wherein such or such catastrophes 
and mutations have happened," see his Posthumous Works, Lecture, 
Feb. 29, 1688. 

[Still more wonderful is the preservation of the substance of the an- 
imal of certain Cephalopodes in the Oxford clay. In some specimens 
recently obtained, and described by Professor Owen, not only the ink 
bag, but the muscular mantle, the head, and its crown of arms, are all 
preserved in connection with the belemnite shell, while one specimen 
exhibits the large eyes and the funnel of the animal, and the remains of 
two fins, in addition to the shell and the ink bag. See Ansted's Ancient 
World, p. 147.]— Tr. 

t Leop. von Buch, in the Abhandlungen der Akad. der Wiss. zti Ber 
lin in dcin Jahr 1837, s. 64. 



PALAEONTOLOGY. 273 

curate comparative anatomy, to throw light on the osteolog- 
ical branch of pala3ontology — the archaeology of organic life ; 
but the actual geognostic views of the doctrine of fossil re- 
mains, the felicitous combination of the zoological character 
with the order of succession, and the relative ages of strata, are 
due to the labors of George Cuvier and Alexander Brongniart. 

The ancient sedimentary formations and those of transi- 
tion rocks exhibit, in the organic remains contained within 
them, a mixture of structures very variously situated on the 
scale of progressively-developed organisms. These strata con- 
tain but few plants, as, for instance, some species of Fuci, 
Lycopodiacese which were probably arborescent, Equisetacese, 
and tropical ferns ; they present, however, a singular associa- 
tion of animal forms, consisting of Crustacea (trilobites with 
reticulated eyes, and Calymene), Brachiopoda {^Spirifer, Or- 
this), elegant Sphseronites, nearly allied to the Crinoidea,* Or- 
thoceratites, of the family of the Cephalopoda, corals, and, 
blended with these low organisms, fishes of the most singular 
forms, imbedded in the upper silurian formations. The fam- 
ily of the Cephalaspides, whose fragments of the species 
Ptei-ichtys were long held to be trilobites, belongs exclusively 
to the devonian period (the old red), manifesting, according 
to Agassiz, as peculiar a type among fishes as do the Ichthy- 
osauri and Plesiosauri among reptiles. t The Goniatites, of 
the tribe of Ammonites,^ are raianifested in the transition 
chalk, in the graywacke of the devonian periods, and even in 
the latest silurian formations. 

The dependence of physiological gradation upon the age of 
the formations, which has not hitherto been shown with per- 
fect certainty in the case of invertebrata,^ is most regularly 
manifested in vertebrated animals. The most ancient of 
these, as we have already seen, are fishes ; next in the order 
of succession of formation, passing from the lower to the up- 
per, come reptiles and mammalia. The first reptile (a Sau- 
rian, the Monitor of Cuvier), which excited the attention of 
Leibnitz, II is found in cuperiferous schist of the Zechstein of 

* Leop. von Buch, Gebirgsformationenvon Russland, 1840, s. 24-40. 

t Agassiz, Monograpkie des Poissons Fossiles du vieux Gres Rovge, 
p. vi. and 4. 

X Leop. von Buch, in the Abhandl. der Berl. Akad., 1838, s. 149-168 ; 
Beyrich, Beitr. zur Kenntniss des Rheinischen Uebergangsgebirges, 1837, 
s. 45. 

$ Agassiz, RecTierches svr les Poissons Fossiles, t. i., Introd., p. xviii. ; 
Davy, Consolation in Travel, dial. iii. 

li A Protosaurus, according to Hermann von Meyer. The rib o{ a 

M 2 



274 COSMOS. 

Thuringia ; the Palasosaurus and Thecodontosaurus of Bris- 
tol are, according to Murchison, of the same age. The Sau- 
rians are found in large numbers in the muschelkalk,* in the 
keuper, and in the oolitic formations, where they are the most 
numerous. At the period of these formations there existed 
Plesiosauri, having long, swan-like necks consisting of thirty 
vertebrae ; Megalosauri, monsters resembling the crocodile, 
forty-five feet in length, and having feet whose bones were 
like those of terrestrial mammalia, eight species of large-eyed 
Ichthyosauri, the Geosaurus or Lacerta gigantea of Som- 
mering, and, finally, seven remarkable species of Pterodac- 
tyles,t or Saurians furnished with membranous wings. In 
the chalk the number of the crocodilial Saurians diminishes, 
although this epoch is characterized by the so-called crocodile 
of Maestricht (the JVIososaurus of Couybeare), and the colos- 
sal, probably graminivorous Iguanodon. Cuvier has found 
animals belonging to the existing families of the crocodile in 
the tertiary formation, and Scheuchzer's antediluvian man 
{liomo diluvii testis), a large salamander allied to the Ax- 
olotl, which I brought with me from the large Mexican lakes, 
belongs to the most recent fresh-water formations of CEnin- 

^^"•i . . . . ■ 

The determination of the relative ages of organisms by the 

superposition of the strata has led to important results regard- 
ing the relations which have been discovered between extinct 
families and species (the latter being but few in number) and 
those which" still exist. Ancient and modern observations 
concur in showing that the fossil floras and faunas differ more 
from the present vegetable and animal forms in proportion as 
they belong to lower, that is, more ancient sedimentary for- 
mations. The numerical relations first deduced by Cuvier 

Saurian asserted to have been found in the mountain limestone (car- 
bonate of lime) of Northumberland (Herm. von Meyer, Palceologica, s. 
299), is regarded by Lyell {Geology, 1832, vol. i., p. 148) as very doubt- 
ful. The discoverer himself referred it to the alluvial strata which 
cover the mountain limestone. 

* F. von Alberti, Monographie des Bunten Sandsteins, Musclielkalk» 
und Keupers, 1834, s. 119 und 314. 

t See Hermann von Meyer's ingenious considerations regarding the 
organization of the flying Saurians, in his Palceologica, s. 228-252. In 
the fossil specimen of the Pterodactylus crassirostris, which, as well as 
the longer known P. longii'ostris (Ornithocephalus of Sommering), was 
found at Solenhofen, ir the lithographic slate of the u[)per Jura forma- 
tion, Professor Goldfass has even discovered traces of the membranous 
wing, "with the impressions of cui'ling tufts of hair, in some places a 
full inch in length." t [Ansted's Ancient World, p. .56.] — 7V. 



PALAEONTOLOGY. 21 J 

from ihe great phenomena of the metamorphism of organic 
life,* have led, through the admirable labors of Deshayes and 
Lyell, to the most marked results, especially with reference to 
the difiereiit groups of the tertiary formations, which contain 
a considerable number of accurately investigated structures. 
Agassiz, who has examined 1700 species of Ibssil fishes, and 
who estimates the number of living species which have either 
been described or are preserved in museums at 8000, expressly 
Bays, in his masterly work, that, "with the exception of a few 
small fossil fishes peculiar to the argillaceous geodes of Green- 
land, he has not found any animal of this class in all the tran 
sition, secondary or tertiary formations, which is specificall) 
identical with any still extant fish." He subjoins the im- 
portant observation " that in the lower tertiary formations, 
for instance, in the coarse granular calcareous beds, and in the 
London clay,t one third of the fossil fishes belong to wholly 
extinct families. Not a single species of a still extant family 
is to be found under the chalk, while the remarkable family 
of the Sauroidi (fishes with enameled scales), almost allied 
to reptiles, and which are found from the coal beds — in which 
the larger species lie — to the chalk, where they occur individ- 
ually, bear the same relation to the two families (the Lepi- 
dosteus and Polyp terus) which inhabit the American rivers 
and the Nile, as our present elephants and tapirs do to the 
Mastodon and Anaplotheriun of the primitive world. "$ 

The beds of chalk which contain two of these sauroid fishes 
and gigantic reptiles, and a whole extinct world of corals and 
muscles, have been proved by Ehrenberg's beautiful discov- 
eries to consist of microscopic Polythalamia, many of which 
still exist in our seas, and in the middle latitudes of the Nortli 
Sea and Baltic. The first group of tertiary formations above 
the chalk, which has been designated as belono^in^ to the 
Eocene Period, does not, therefore, merit that designation, 
since " the daimi of the ivorld in which we live extends mu di 
further back in the history of the past than we have hithe) to 
supposed." § 

As we have already seen, fishes, which are the most ancient 
of all vertebrata, are found in the silurian transition strata, 

* Cuvier, Recherches sur les Ossemens Fossiles, t. i., p. 52-57. See, 
also, the geological scale of epochs in Phillips's Geology, 1837, p. lG(i- 
185. t [See Wonders of Geology, yoi. i., p. 230.]— Tr 

X As;a.si\z, Poissons Fossiles, t. i., p. 30, and t. iii., p. 1-5-2; l)iifk- 
land. Geology, vol. i., p. 273-277. 

§ Ehrenberg, Ue'jer noch jetzt lehende Thierarten der KreUehiUhnig, 
in the Ahhandl. der Berliner Aknd., 1839, 8. 164. 



276 * COSMOS. 

and then uninterruptedly on through all formations to the 
strata of the tertiary period, while Saurians begin with the 
zechstone. In like manner, we find the first mammalia 
( Thylacotheriimi Prevostii, and T. Bucklandii, which are 
nearly allied, according to Valenciennes,* with marsupial an- 
imals) in the oolitic formations (Stonesfield schist), and the 
first birds in the most ancient 6retaceous strata. t Such are, 
according to the present state of our knowledge, the lowest$ 
limits of fishes, Saurians, mammalia, and birds. 

Although corals and Serpulidas occur in the most ancient 
formations simultaneously with highly-developed Cephalopodes 
and Crustaceans, thus exhibiting the most various orders 
grouped together, we yet discover very determinate laws in 
the case of many individual groups of one and the same or- 
ders. A single species of fossil, as Goniatites, Trilobites, or 
Nummulites, sometimes constitutes whole mountains. Where 
difierent families are blended together, a determinate succes- 
sion of organisms has not only been observed with reference 
to the superposition of the formations, but the association of 
certain families and species has also been noticed in the lower 
strata of the same formation. By his acute discovery of the 
arrangement of the lobes of their chamber-sutures, Leopold 
von Buch has been enabled to divide the innumerable quan- 
tity of Ammonites into well-characterized families, and to 
show that Ceratites appertain to the muschelkalk, Arietes to 
the lias, and Goniatites to transition limestone and graywacke.§ 
The lower limits of Belemnites are, in the keuper, covered by 
Jura limestone, and their upper limits in the chalk forma- 
tions. || It appears, from what we now know of this subject, 
that the waters must have been inhabited at the same epoch, 
and in the most widely-remote districts of the- world, by shell- 
fish, which were, at any rate, in part, identical with the fossil 
remains found in England. Leopold von Buch has discovered 
exogyra and trigonia in the southern hemisphere (volcano of 

* Valenciennes, in the Comptes Rendus de V Acadimie des Sciences, t. 
vii., 1838, Part ii., p. 580. 

t la the Weald clay; Beudant, Giologie, p. 173. The ornitholite* 
increase in number in the gypsum of the tertiary formations. Cuvier 
Ossemens Fossiles, t. ii., p. 302-328. 

t [Recent collections from the southern hemisphere show that this 
distribution was not so universal during the earlier epochs as has gen- 
erally been supposed. See papers by Darwin, Sharpe, Morris, and 
M'Coy, in the Geological Journal.'] — Tr. 

$ Leop, von Buch, in the Abhandl. der Berl. Akad., 1830, s. 135-187 

II Quenstedt, Fldizgehirge Wnrfemhergs, 1843, s. 135. 



PALEONTOLOGY. 277 

Maypo in Chili), and D'Orbigny lias "described Ammonites 
and Gryphites from the Himalaya and the Indian plains of 
Cutch, these remains being identical with those found in the 
old Jurassic sea of Germany and France. 

The strata which are distinguished by definite kinds of pet- 
rifactions, or by the fragments contained within them, form 
a geognostic horizon, by which the inquirer may guide his 
steps, and arrive at certain conclusions regarding the identity 
or relative age of the formations, the periodic recurrence of 
certain strata, their parallelism, or their total suppression. If 
we classify the type of the sedimentary structures in the sim- 
plest mode of generalization, we arrive at the following series 
in proceeding from below upward : 

1. The so-called tra7isitmn rocks, in the two divisions of 
upper and lower graywacke (silurian and devonian systems), 
the latter being formerly designated as old red sandstone. 

2. The lower trias* comprising mountain limestone, coal- 
measures, together with the lower new red sandstone (Todt- 
liegende and Zechstein).t 

3. The upper trias, including variegated sandstone, t mu* 
chelkalk, and keuper. 

4. Jura limestone (lias and oolite). 

5. Green sandstone, the quader sanstein, upper and lower 
chalk, terminating the secondary formations, which begin with 
limestone. 

6. Tertiary forynations in three divisions, distinguished as 
granular limestone, the lignites, and the sub-Apennine gravei 
of Italy. 

Then follow, in the alluvial beds, the colossal bones of the 
mammalia of the primitive world, as the mastodon, dinothe- 

* Queustedt, Flotzgebirge Wurtembergs, 1843, s. 13. 

t IMurchison makes two divisions of the hunter sandstone, the upper 
being the same as the trias of Alberti, while of the lower division, to 
which the Vosges sandstone of Elie de Beaumont belongs — the zeck' 
stein and the todtliegende — he forms his Permian system. He makes 
the secondary formations commence with the upper trias, that is to say, 
with the upper division of our (German) bunter sandstone, w hile the 
Permian system, the carboniferous or mountain limestone, and the 
devonian and silurian sti'ata, constitute his palaeozoic formations. Ac- 
cording to these views, the chalk and Jura constitute the upper, and 
the keuper, the muschelkalk, and the hunter sandstone the lower sec- 
ondary formations, while the Permian system and the carboniferous 
limestone are the upper, and the devonian and silurian strata are the 
lower palaeozoic fonnation. The fundamental principles of this general 
classification are developed in the great work in which this indefaliga« 
ble British geologist purposes to describe the geology of a large part of 
Eastern Europe. 



278 COSMOS. 

rium, missniium, and the megatlierides, among which is 
Owen's sloth-like mylodon, eleven feet in length.* Besides 
these extinct families, we find the fossil remains of still extant 
animals, as the elephant, rhinoceros, ox, horse, and stag. The 
field near Bogota, called the Ca^njoo de Gigantes. which is 
filled with the hones of mastodons, and in which 1 caused ex- 
cavations to be made, lies 8740 feet above the level of the 
Bea, while the osseous remains, found in the elevated plateaux 
of Mexico, belong to true elephants of extinct species. t The 
projecting spurs of the Himalaya, the Sewalik Hills, which 
have been so zealously investigated by Captain CautleyJ and 
Dr. Falconer, and the Cordilleras, whose elevations are, prob- 
ably, of very different epochs, contain, besides numerous mas- 
todons, the sivatherium, and the gigantic land tortoise of the 
primitive world (Colossochelys), which is twelve feet in length 
and six in height, and several extant families, as elephants, 
rhinoceroses, and giraffes ; and it io a remarkable fact, that 
these remains are found in a zone which still enjoys the same 
tropical climate which must be supposed to have prevailed at 
the period of the mastodons.^ 

Having thus passed in review both the inorganic formations 
of the earth's crust and the animal remains which are con- 
tained within it, another branch of the history of organic life 
still remains for our consideration, viz., the epoch of vegcta 
tion, and the successive floras that have occurred simul- 
taneously with the increasing extent of the dry land and the 
modifications of the atmosphere. The oldest transition strata, 
as we Jbave already observed, contain merely cellular marine 
plants, and it is only in the devonian system that a few cryp- 
togamic forms of vascular plants (Calamites and Lycopodi- 
acese) have been observed. II Nothing appears to corroborate 

* [See Mantell's Wonders of Geology, vol. i., p. 168.]— Tr. 

t Olivier, Ossemens Fossiles, 1821. t. i., p. 157, 261, and 264. See, 
also, Humboldt, Ueber die Hochebene von Bogota, in the Devtschen 
Vierteljahrs-schrift, 1839, bd. i., s. 117. 

t [The fossil fauna of the Sewalik range of hills, skirting the south- 
ern base of the Himalaya, has proved more abundant in genera nnd 
species of mammalia than that of any other I'egioii yet explored. As 
a general expression of the leading features, it may be stated, that it 
appears to have been composed of representative forms of all ages, 
from the oldest of the tertiary period down to the modern, and o{ all tht 
geographical divisions of the Old Continent groupe<l tofjether into Oiie 
comprehensive fauna. Fauna Antiqita Sivalicnsis, by Hu^h Falconer. 
M.D., and iMajor P. T. Oautley.]— Tr. 

§ Journal of the Asiatic Society, 1844, No. 15, p. 109. 

II Beyrich, in Karsten's Archivfar Mlneralogie, 1844. bd. xviii., s. 218 



PALAEONTOLOGY. 279 

the theoretical views that have been started rejravdinjr the 
simphcity of primitive forms of organic Hfe, or that vegetable 
preceded animal lile, and that the former was necessarily de- 
pendent upon the latter. The existence of races of men in- 
habiting the icy regions of the North Polar lands, and whose 
nutriment is solely derived from lish and cetaceans, shows the 
possibility of maintaining life independently of vegetable sub- 
stances. After the devonian system and the mountain lime- 
stone, we come to a formation, the botanical analysis oi" which 
has made such brilliant advances in modern times.* The 
coal measures contain not only fern- like cryptogamic plants 
and phanerogamic monocotyledons (grasses, yucca-like Lilia- 
cea3, and palms), but also gymnospermic dicotyledons (Coniferte 
and Cycadeas), amounting in all to nearly 400 species, as char- 
acteristic of the coal formations. Of these we will onlv enu- 
merate arborescent Calamites and Lycopodiacese, scaly Lepi- 
dodendra, Sigillarise, which attain a height of sixty feet, and 
are sometimes found standing upright, being distinguished by 
a double system of vascular bundles, cactus-like Stigmarite, a 
great number of ferns, in some cases the stems, and in others 
the fronds alone being found, indicating by their abundance 
the insular form of the dry land,t Cycadea3,$ especially palms, 
although fewer in number,^ Asterophyllites, having whorl-like 
leaves, and allied to the Naiades, with araucaria-like Coniferse,!! 
which exhibit faint traces of annual rings. This difference of 
character from our present vegetation, manifested in the vege- 
tative forms which were so luxuriously developed on the drier 

* By the important labors of Couut Sternberg, Adolphe Brougniart, 
Goppert, and Lindley. 

t See Robert Brown's Botany of Congo, p. 42, and the Memoir of 
the unfortunate D'Urville, De la Distribution des Fougeres sur la Sur- 
face du Globe Terrestre. 

X Such are the Cycadeae discovered by Count Sternberg in the old 
carboniferous formation at Radnitz, in Bohemia, and described by 
Corda (two species of Cycatides and Zamites Cordai. See Goppert, 
Fossile Cycadeen in den Arbeiten der Schles. GeseUschaft, fur vaterl. 
Cultur im Jahr 1843, s. 33, 37, 40, and 50). A Cycadea (Pterophyllum 
gonorrhachis, Gopp.) has also been found in the carboniferous forma- 
tions in Upper Silesia, at Konigshtitte. 

$ Lindley, Fossil Flora, No. xv., p. 163. 

II Fossil Coniferce, in Buckland's Geology, p. 483-490. Witham has 
the great merit of having first recognized the existence of Coniferse in 
the early vegetation of the old carboniferous formation. Almost all the 
trunks of trees found in this formation were previously regarded as 
palms. The species of the genus Arancaria are, however, not pecul- 
iar to the coal formations of the British Islands; they likewise occur in 
Upper Silesia. 



280 cu^.^iori. 

and more elevated portions of the old red sandstone, was main« 
tained through all the subsequent epochs to the most recent 
chalk formations ; amid the peculiar characteristics exhibited 
in the vejretable forms contained in the coal measures, there 
is, however, a strikingly-marked prevalence of the same fami- 
lies, if not of the same species,^ in all parts of the earth as it 
then existed, as in New Holland, Canada, Greenland, and 
Melville Island. 

The vegetation of the primitive period exhibits forms v/hich, 
from their simultaneous affinity w^ith several families of the 
present world, testify that many intermediate links must have 
become extinct in the scale of organic development. Thus, 
for example, to mention only two instances, we would notice 
the Lepidodendra, which, according to Lindley, occupy a place 
between the Coniferse and the Lycopodiaceee,! and the Arau- 
carise and pines, which exhibit some peculiarities in the union 
of their vascular bundles. Even if we limit our consideration 
to the present world alone, we must regard as highly import- 
ant the discovery of Cycadese and Conifera3 side by side with 
SagenariaB and Lepidodendra in the ancient coal measures. 
The Coniferee are not only allied to Cupuliferaj and Betuliuce, 
with which we find them associated in lignite formations, but 
also with Lycopodiacese. The family of the sago-like Cyca- 
dese approaches most nearly to palms in its external appear- 
ance, while these plants are specially allied to Conifers in re- 
spect to the structure of their blossoms and seed.J Where 
many beds of coal are superposed over one another, the fami- 
lies and species are not always blended, being most frequently 
grouped together in separate genera ; Lycopodiacese and cer- 
tain ferns being alone found in one bed, and Stigmariae and 
Sigillarise in another. In order to give some idea of the lux- 
uriance of the vegetation of the primitive world, and of the 
immense masses of vegetable matter which was doubtlessly 
accumulated in currents and converted in a moist condition 
into coal,§ I would instance the Saarbriicker coal measures, 

* Adolphe Brongniart, Prodrome d'vne Hist, des VegUaux Fossiles, p. 
179 ; Buckland, Geology, p. 479; Eudlicher and Unger, Grundzuge der 
Boianik, 1843, s. 455. 

t " By means of Lepidodeudron, a better passage is established from 
flowering to flowerless plants than by either Equisetum or Cycas, or 
any other known genus." — Lindley and Hiitton, Fossil Flora, vol. ii., 
p. 53. 

X Kunth, Anordnnng der Pflanzenfamilien, in his Handb. der Bof.anik 
8. 307 und 314. 

§ That coal has not been formed froui veii('tM])]r! ii!)es clianed bv 



PALAEONTOLOGY. 281 

where 120 beds are superposed on one another, exchisive of a 
great many which are less than a foot in thickness ; the coal 
beds at Johnstone, in Scotland, and those in the Creuzot, in 
Burgundy, are some of them, respectively, thirty and fifty feet 
in thickness,^ while in the forests of our temperate zones, the 
carbon contained in the trees growing over a certain area 
would hardly suffice, in the space of a hundred years, to cover 
it with more than a stratum of seven French lines in thick- 
ness.! Near the mouth of the Mississippi, and in the "w^ood 
hills" of the Siberian Polar Sea, described by Admiral Wran- 
gel, the vast number of trunks of trees accumulated by river 
and sea water currents affords a striking instance of the 
enorm.ou3 quantities of drift-wood which must have favored 
the formation of carboniferous depositions in the inland waters 
and insular bays. There can be no doubt that these beds 
owe a considerable portion of the substances of which they 
consist to grasses, small branching shrubs, and cryptogamic 
plants. 

The association of palms and Coniferee, which we have in- 
dicated as being characteristic of the coal formations, is dis- 
coverable throughout almost all formations to the tertiary 
period. In the present condition of the world, these genera 

fire, but that it has more probably been produced in the moist way by 
the action of sulphuric acid, is stnkingly demonstrated by the excellent 
observation made by Goppert (Karsteu, Archiv fur Mineralogie, bd. 
xviii., s. 530), on the conversion of a fragment of amber-tree into black 
coal. The coal and the unaltered amber lay side by side. Regarding 
the part which the lower forms of vegetation may have had in the for- 
mation of coal beds, see Link, in the Abhandl. der Berliner Akademie 
der Wissenschaften, f838, s. 38. 

* [The actual total thickness of the different beds in Ensland varies 
considerably in diiferent districts, but appears to amount in the Lanca- 
shire coal field to as much as 150 feet. — Ansted's Ancient World, p. 
78. For an enumeration of the thickness of coal measures in America 
and the Old Continent, see Mantell's Wonders of Geology, vol. ii., p. 
69.] — Tr. 

t See the accurate labors of Chevandier, in the Comptes Rendus de 
VAcad^mie des Sciences, 1844, t. xviii., Part i., p. 285. In comparing 
this bed of carbon, seven lines in thickness, with beds of coal, we must 
not omit to consider the enormous pressure to which the latter have 
been subjected from superimposed rock, and which manifests itself in 
the flattened form of the stems of the trees found in these subterranean 
regions. " The so-called wood-hills discovered in 1806 by Sirowatskoi, 
on the south coast of the island of New Siberia, consist, according to 
Hedenstrom, of horizontal strata of sandstone, alternating with bitu- 
minous trunks of ti'ees, forming a mound thirty fathoms in height ; at 
the summit the stems were in a vertical position. The bed of <lrift- 
wood is visible at five wersts' distance." — See Wrangel, Reise Uin^a 
der Nardkuste von Siberian, in den Jahren 1820-24, th. i., s. 102. 



282 COSMOS. 

appear to exhibit no tendency whatever to occur associated 
lofrether. We have so accustomed ourselves, althouofh erro- 
neously, to regard Conifera3 as a northern form, that I experi- 
enced a feehng of surprise when, in ascending from the shores 
of the South Pacific toward Chilpansingo and the elevated 
valleys of Mexico, between the Venta de la Moxonera and the 
Alto de los Caxones, 4000 feet above the level of the sea, I 
rode a whole day through a dense wood of Pinus occidentalis, 
where I observed that these trees, which are so similar to the 
Weymouth pine, were associated with fan palms* {Cori/pha 
dulcis), swarming v/ith brightly-colored parrots. South Amer- 
ica has oaks, but not a single species of pine ; and the first 
time that I again saw the familiar form of a fir-tree, it was 
thus associated with the strange appearance of the fan palm.f 
Christopher Columbus, in his first voyage of discovery, saw 
Coniferaj and palms growing together on the northeastern ex- 
tremity of the island of Cuba, likewise within the tropics, and 
scarcely above the level of the sea. This acute observer, 
whom nothing escaped, mentions the fact in his journal as a 
remarkable circumstance, and his friend Anghiera, the secre- 
tary of Ferdinand the Catholic, remarks with astonishment 
" that jKdmeta and inneta are found associated together in 
the newly-discovered land." It is a matter of much import- 
ance to geology to compare the present distribution of plants 
over the earth's surface w4th that exhibited in the fossil floras 
of the primitive world. The temperate zone of the southern 
hemisphere, which is so rich in seas and islands, and v/here 

* This corypha is the snyate (in Aztec, zoyall')'o" the Palma dulce of 
the natives. See Huiuboklt auJ Bonplaiid. Synopt^ls Plant, ^^quinoct. 
Oihis Novi, t. i., p. 302. Professor Buschmaiin, who is profoundly ac- 
quaiuted with the American languages, remarks, that the Palma soy ate 
is so named in Yepe's Vocabulario de la Lengua Othomi, and that the 
Aztec word zoyatl (Molina, Vocabulario en Lengua Mexicana y Castel- 
lana, p. 25) recurs in uames of places, such as Zoyatitlan and Zoya- 
pauco, near Chiapa. 

t Near Baracoa and Cayos de Moya. See the Admiral's journal of 
the 2.5th and 27th of November, 1492, and Humboldt, Examen Critique 
de V Hist, de la Giographie du Nouveau Continent, t. ii., p. 252, and t. 
iii., p. 23. Columbus, who invariably paid the most remarkable atten- 
tion to all natural objects, v/as the first to observe the ditference be- 
tween Podocarpus and Pinus. " I find," said he, " en la tierra aspera 
del Cibao pinos que no llevan pinas (fir cones), pero portal orden com- 
puestos por naturaleza, que (los frutos) pareceu azeytimas del Axarafe 
de Sevilla." The great botanist, Richard, when he published his ex- 
cellent Memoir on Cycade;Te and Conifene, little imagined that before 
the time of L'Heritier, and even before the end of the fifteenth cen- 
tury, a navigator had separated Podocarjyns from the Abietineoe. 



PALiEONTOLOGY. 283 

tropical forms blend so remarkably with those of colder parts 
of the earth, presents, according to Darwin's beautiful and 
animated descriptions,* the most instructive materials for the 
study of the present and the past geography of plants. The 
history of the primordial ages is, in the strict sense of the 
word, a part of the history of plants. 

CycadesB, which, from the number of their fossil species, must 
have occupied a far more important part in the extinct than 
in the present vegetable world, are associated with the nearly 
allied Coniferffi from the coal formations upward. They are 
almost wholly absent in the epoch of the variegated sandstone 
which contains Coniferse of rare and luxuriant structure ( Vol- 
tizia, Ilaidingera, Albertia) ; the. Cycadeae, however, occur 
most frequently in the keuper and lias strata, in which more 
than twenty diilerent forms appear. In the chalk, marine 
plants and naiades predominate. The forests of Cycadeae of 
the Jura formations had, therefore, long disappeared, and even 
in the more ancient tertiary formations they are quite subor- 
dinate to the Coniferce and palms. t 

The lignites, or beds of brown coalt which are present in 
all divisions of the tertiary period, present, among the most 
ancient cryptogami i land plants, some few palms, many Co- 
nifera3 having distinct annual rings, and foliaceous shrubs of a 
more or less tropical character. In the m^iddle tertiary period 
we again find palms and Cycadese fully established, and final- 
ly a great similarity with our existing Hora, manifested in the 
sudden and abundant occurrence of our pines and firs, Cupu- 
lifei'ce, maples, and poplars. The dicotyledonous stems found 
in lisnite are occasionally distinguished bv colossal size and 
great age. In the trunk of a tree found at Bonn, Noggerath 
counted 792 annual rings. ^ In the north of France, at Yseux, 
near Abbeville, oaks have been discovered in the turf moors 
of the Somme which measured fourteen feet in diameter, a 
thickness which is very remarkable in the Old Continent and 
without the tropics. According to Goppert's excellent inves- 
tigations, which, it is hoped, may soon be illustrated by plates^- 
it would appear that " all the amber of the Baltic comes from 

* Charles Darv/in, Journal of the Voyages of the Adventure and 
Beagle, 1839, p. 271. 

t GSppert describes three other Cycade.np (species of Cycadites and 
Plerophyllam), tbuud in the brown carboniferous schistose clay <>f Alt- 
sattel and Coinniotuu, in Bohemia. They very probably belong to tho 
Eocene Period. Gopperf, Fossile Cycadecn, .s. fil, 

X \_Medals of Creation, vol. i., cli. v., &c. Wonders of Geology, vol. i., 
p. 278, 392.] — YV. $ Bnckland, Geology, p. .^)09. 



284 COSMOS. 

a coniferous tree, which, to judge by the still extant remama 
of the wood and the bark at different ages, approaches very 
nearly to our white and red pines, although forming a distinct 
species. The amber-tree of the ancient world {Pijzites succi- 
fer) abounded in resin to a degree far surpassing that mani- 
lested by any extant coniferous tree ; for not only were large 
masses of amber deposited in and upon the bark, but also iu 
the wood itself, following the course of the medullary rays, 
which, together with ligneous cells, are still discernible under 
the microscope, and peripherally between the rings, being some 
times both yellow and white." 

" Among the vegetable forms inclosed in amber are male 
and female blossoms of our native needle-v/ood trees and Cupu- 
liferjB, while fragments which are recos^nized as belonoiuor tc 
thuia, cupressus, ephedera, and castania vesca, blended wdtk 
those of junipers and firs, indicate a vegetation difierent fronr 
that of the coasts and plains of the Baltic. "=^ 

We have now passed through the whole series of formationa 
comprised in the geological portidn of the present work, pro- 
ceeding from the oldest erupted rock and the most ancient sed- 
imentary formations to the alluvial land on which are scat- 
tered those large masses of rock, the causes of whose general 
distribution have been so long and variously discussed, and 
which are, in my opinion, to be ascribed rather to the pene- 
tration and violent outpouring of pent-up waters by the eleva- 
tion of mountain chains than to the motion of floating blocks 
of ice.f The most ancient structures of the transition forma- 

* [The forests of ambcr-piiie?, Pinites succifer, were iu the southeast- 
ei'n part of what is now the bed of the Baltic, iu about .5.5° N. lat., 
and 37° E. long. The different colors of amber are derived from local 
chemical admixture. The amber contains fragments of vegetable mat- 
ter, and from these it has been ascertained that the amber-pine forests 
contained four other species of pine (besides the Pinites succifer), sev- 
eral cypresses, yews, and jiuiipers, with ouks, poplars, beeches, &c. — 
altogether forty-eight species of trees and shrubs, constituting a flora 
of North American character. There are also some ferns, mosses, fungi, 
and liverworts. See Professor Goppert, Geo/. Trans., I'Si^b. Insects, spi- 
ders, small crustaceans, leaves, and fragments of vegetable tissue, are 
imbedded in some of the masses. Upward of 800 species of insects 
have been observed; most of them belong to species, and even genera, 
that appear to be distinct from any now known, but others are nearly 
related to indigenous species, and some are identical with existing forms, 
that inhabit mjre southern climes. — Wonders of Geology, vol. i., p. 242, 
&c.]— Tr. 

+ Leopold von Buch, iu the Ahhandl. der Akad. der Wissensch . zu 
Berlin, 1814-15, s. 161 ; and in Poggend., Annalen. bd. ix.. s. 57-'» • '''i** 
de Pu'uumout, in the Annales des Sciences Nalnrelles, t. xi.\., p. 0^ 



. GEOGNOSTIC PERIODS. 285 

tion with which we are acquainted are slate and gra^wacke, 
which contain some remains of sea weeds from the silurian or 
Cambrian sea. On what did these so-called 7?iost ancie?U for- 
mations rest, if gneiss and mica schist must be regarded as 
changed sedimentary strata? Dare we hazard a conjecture 
on that which can not be an object of actual geognostic observ- 
ation ? According to an ancient Indian myth, the earth is 
borne up by an elephant, who in his turn is supported by a 
gigantic tortoise, in order that he may not fall ; but it is not 
permitted to the credulous Brahmins to inquire on what the 
tortoise rests. We venture here upon a somewhat similar 
problem, and are prepared to meet with opposition in our en- 
deavors to arrive at its solution. In the first formation of the 
planets, as we stated in the astronomical portion of this work, 
it is probable that nebulous rings revolving round the sun were 
agglomerated into spheroids, and consolidated by a gradual 
condensation proceeding from the exterior toward the center. 
What we term the ancient silurian strata are thus only the 
upper portions of the sohd crust of the earth. The erupted 
rocks which have broken through and upheaved these strata 
have been elevated from depths that are wholly inaccessible 
to our research ; they must, therefore, have existed under the 
silurian strata, and been composed of the same association of 
minerals which we term granite, augite, and quartzose por- 
phyry, when they are made known to us by eruption through 
the surface. Basing our inquiries on analogy, we may assume 
that the substances which fill up deep fissures and traverse the 
sedimentary strata are merely the ramifications of a lower de- 
posit. The foci of active volcanoes are situated at enormous 
depths, and, judging from the remarkable fragments which I 
have found in various parts of the earth incrusted in lava cur- 
rents, I should deem it more than probable that a primordial 
granite rock forms the substratum of the whole stratified edi- 
fice of fossil remains.* Basalt containing olivine first shows 
itself in the period of the chalk, trachyte still later, while erup- 
tions of granite belong, as we learn from the products of their 
metamorphic action, to the epoch of the oldest sedimentary 
strata of the transition formation. Where knowledge can not 
be attained from immediate perceptive evidence, we may be 
allowed from induction, no less than from a careful comparison 
of facts, to hazard a conjecture by which granite would be re- 

* See Elie de Beaumont, Descr. G^ol. de la France, t. i., p. 6.5 ; Beu 
dant, Giologie, 1844, p. 1(\d. 



286 COSMOS. 

stored to a portion of its Contested right and title tD be consid- 
ered as a iiriinnrdial rock. 

The recent progress of" geognosy, that is to say, the more 
extended knowledge of the geognostic epochs characterized by 
difference of mineral formations, by the peculiarities and suc- 
cession of the organisms contained within them, and by the 
position of the strata, whether uplifted or inclined horizontally 
leads us, by means of the causal connection existing among all 
natural phenomena, to the distribution of solids and fluids into 
the continents and seas which constitute the upper crust of our 
planet. We here touch upon a point of contact between geo- 
logical and geographical geognosy which would constitute the 
complete history of the form and extent of continents. The 
limitation of the solid by the fluid parts of the earth's surface 
and their mutual relations of area, have varied very consider- 
ably in the long series of geognostic epochs. They Avere veiy 
different, for instance, when carboniferous strata were horizon- 
tally deposited on the inclined beds of the mountain limestone 
and old red sandstone ; when lias and oolite lay on a substra- 
tum of keuper and muschelkalk, and the chalk rested on the 
slopes of green sandstone and Jura limestone. If, with Elie 
de Beaumont, we term the waters in which the Jura limestone 
and chalk formed a soft deposit the Jui'assic or oolitic, and the 
creto.ceous, seas, the outlines of these formations will indicate, 
for the two corresponding epochs, the boundaries between the 
already dried land and the ocean in which these rocks were 
forming. An ingenious attempt has been made to draw maps 
of this physical portion of primitive geography, and we may 
consider such diagrams as more correct than those of the v\^an- 
derings of lo or the Homeric geography, since the latter are 
merely graphic representations of mythical images, while the 
former are based upon positive facts deduced from the science 
of geology. 

The results of the investigations made regarding the areal 
relations of the solid portions of our planet are as follows : in 
the most ancient times, during the silurian and devonian tran- 
sition epochs, and in the secondary formations, including the 
trias, the continental portions of the earth were limited to in- 
sular groups covered with vegetation ; these islands at a sub- 
sequent period became united, giving rise to numerous lakes 
and deeply-indented bays ; and, finally, when the chains of 
the Pyrenees, Apennines, and Carpathian Mountains were 
elevated about the period of the more ancieiit tertiary forma- 
tions, large contiueiits appeared, having almost their prcscui 



PHYSICAL GEOGRAPHY. 287 

size.* Ill the silurian epoch, as well as in that in which the Cy- 
cadeee flourished in such abundance, and gigantic saurians were 
living, the dry land, from pole to pole, was probably less than it 
now is in the South Pacific and the Indian Ocean. We shall 
see, in a subsequent part of this work, how this prepondera- 
ting quantity of water, combined with other causes, must have 
contributed to raise the temperature and induce a greater uni- 
formity of climate. Here we would only remark, in consider- 
ing the gradual extension of the dry land, that, shortly before 
the disturbances which at longer or shorter intervals caused 
the sudden destruction of so great a number of colossal verte- 
brata in the diluvial 'period, some parts of the present conti- 
nental masses must have been completely separated from one 
another. There is a great similarity in South America and 
Australia between still living and extinct species of animals. 
In New Holland fossil remains of the kangaroo have been 
found, and in New Zealand the semi-fossilized bones of an enor- 
mous bird, resembling the ostrich, the dinornis of Owen, f which 
is nearly allied to the present apteryx, and but little so to the re- 
cently extinct dronte (dodo) of the island of Rodriguez. 

The form of the continental portions of the earth may, per- 
haps, in a great measure, owe their elevation above the sur- 
rounding level of the water to the eruption of quartzose por- 
phyry, which overthrew with violence the first great vegeta- 
tion from which the material of our present coal measures was 
formed. The portions of the earth's surface which v»'e term 
plains are nothing more than the broad summits of hills and 
mountains whose bases rest on the bottom of the ocean. Every 
plain is, therefore, when considered according to its submarine 
relations, an elevated plateau, whose inequahties have been 
covered over by horizontal deposition of new sedimentary for- 
mations and by the accumulation of alluvium. 

* [These movements, described in so few words, were doubtless go 
ing on tor many thousands and tens of thousands of revolutions of our 
planet. They were accompanied, also, by vast but slow changes of other 
kinds. The expansive force employed in lifting up, by mighty move- 
ments, the northern portion of the continent of Asia, found partial vent ; 
and from partial subaqueous fissures there were poured out the tabular 
masses of basalt occurring in Central India, while an extensive area of 
depression in the Indian Ocean, marked by the coral islands of the Lac- 
cadives, the Maldives, the great Chagos Bank, and some others, were 
in the course of depression by a counteracting movement. — Ansted'a 
Ancient World, p. 346, &c.]— Tr. 

+ [See American Journal of Science, vol. xlv., j). 187 ; nnd Medals 
of Creation, vol. ii., ]i. 817 ; Trans. Zoolog. Society of London, vol. ii. : 
Wonders of Geolcry, vol. i., p. rJ9.]— Tv. 



288 COSMOS. 

Among the general subjects of contemplation appertaining 
to a work of this nature, a prominent place must be given, first, 
to the consideration of the qucmiity of the land raised above 
the level of the sea, and, next, to the individual configuration 
of each part, either in relation to horizontal extension (rela- 
tions of form) or to vertical elevation (hypsometrical relations 
of mountain-chains). Our planet has tv^^o envelopes, of which 
one, which is general — the atmosphere — is composed of an 
elastic fluid, and the other — the sea — is only locally distribu- 
ted, surrounding, and therefore modifying, the form of the land. 
These two envelopes of air and sea constitute a natural whole, 
on which depend the difference of climate on the earth's sur- 
face, according to the relative extension of the aqueous and 
solid parts, the form and aspect of the land, and the direction 
and elevation of mountain chains. A knowledge of the recip- 
rocal action of air, sea, and land teaches us that great me- 
teorological phenomena can not be comprehended when consid- 
ered independently of geognostic relations. Meteorology, as 
well as the geography of plants and animals, has only begun 
to make actual progress since the mutual dependence of the 
phenomena to be investigated has been fully recognized. The 
word climate has certainly special reference to the character 
of the atmosphere, but this character is itself dependent on the 
perpetually, concurrent influences of the ocean, which is uni- 
versally and deeply agitated by currents having a totally oppo- 
site temperature, and of radiation from the dry land, which va- 
ries greatly in form, elevation, color, and fertility, whether we 
consider its bare, rocky portions, or those that are covered with 
arborescent or herbaceous vegetation. 

In the present condition of the surface of our planet, the area 
of the solid is to that of the fluid parts as 1 : 2|ths (accord- 
ing to E-igaud, as 100 : 270).'* The islands form scarcely g-^d 
of the continental masses, which are so unequally divided that 
they consist of three times more land in the northern than in 
the southern hemisphere ; the latter being, therefore, pre-emi- 
nently oceanic. From 40'-' south latitude to the Antarctic 
pole the earth is almost entirely covered with water. The 
fluid element predominates in like manner between the east- 
ern shores of the Old and the western shores of the New Con- 
tinent, being only interspersed with some few insular groups. 
The learned hydrographer Fleurieu has very justly named this 

* See Transactions of the Cambridge Philosopliical Societ'j. vrl. vi , 
Pai-t ii., 1837, p. 297. Other writers have given the ratb as lOP : 281. 



PHYSICAL GEOGRAPHY. 289 

vast oceanic basin, which, under the tropics, extends over 145^ 
of longitude, the Great Ocean, in contradistinction to all other 
seas. The southern and western hemispheres (reckoning the 
latter from the "meridian of Tenerifle) are therefore more rich 
iw. water than any other region of the whole earth. 

These are the main points involved in the consideration of 
the relative quantity of land and sea, a relation which exer- 
cises so important an influence on the distribution of temper- 
ature, the variations in atmospheric pressure, the direction 
of the winds, and the quantity of moisture contained in the 
air, with which the development of vegetation is so essentially 
connected. When we consider that nearly three fourths ol 
the upper surface of our planet are covered with water,* we 
shall be less surprised at the imperfect condition of meteorol- 
ogy before the beginning of the present century, since it is only 
during the subsequent period that numerous accurate observa- 
tions on the temperature of the sea at different latitudes and 
at different seasons have been made and numerically compared 
together. 

The horizontal configuration of continents in their general 
relations of extension was already made a subject of intellectual 
contemplation by the ancient Greeks. Conjectures were ad- 
vanced regarding the maximum of the extension from west to 
east, and Dicsearchus placed it, according to the testimony of 
Agathemerus, in the latitude of Rhodes, in the direction of a 
line passing from the Pillars of Hercules to Thine. This line, 
which has been termed the 'parallel of the diaphragm of Di- 
ccEarchus, is laid down with an astronomical accuracy of po- 
sition, which, as I have stated in another work, is well worthy 
of exciting surprise and admiration.! Strabo, who was proba- 
bly influenced by Eratosthenes, appears to have been so firmly 
convinced that this parallel of 36^ was the maximum of the 
extension of the then existing world, that he supposed it had 
some intimate connection with the form of the earth, and 
therefore places under this line the continent whose existence 

* lu the Middle Ages, the opinion prevailed that the sea covered ^my 
one seventh of the surface of the globe, au opinion which Cardinal d'Ailly 
(Imago Mundi, cap. 8) founded on the fourth apocrj'^phal book of Esdras. 
Columbus, wfho derived a great portion of his cosmographical knowledge 
from the cai"diaal's work, w^as much interested in upholding this idea 
of the smallness of the sea, to which the misunderstood expression of 
" the ocean stream" contributed not a httle. See Humboldt, Examen 
CrUiquede VHist. de la Giograpkie, t. i., p. 186. 

t Agathemerus, in Hudson, Geographi Minores, t. ii,, p. '1. Seo 
Humboldt, Asie Cetdr., t i.. p. 120-1-2.3, 

Vol. I.— N 



290 coSiMos. 

he divined in the northern hemisphere, between Theria and 
the coasts of Thine. =^ 

As we have ah'eady remarked, one hemisphere of the earth 
(whether we divide the sphere through the equator or through 
the meridian of Teneriffe) has a much greater expansion of 
elevated land than the opposite one : these two vast ocean- 
girt tracts of land, which we term the eastern and western, 
or the Old and New Continents, present, however, conjointly 
with the most striking contrasts of configuration and position 
of their axes, some similarities of form, especially with refer- 
ence to the mutual relations of their opposite coasts. In the 
eastern continent, the predominating direction — the position 
of the major axis — inclines from east to west (or, more cor- 
rectly speaking, from southwest to northeast), while in the 
western continent it inclines from south to north (or, rather, 
from south-southeast to north-northwest). Both terminate to 
the north at a parallel coinciding nearly with that of 70^. 
while they extend to the south in pyramidal points, having 
submarine prolongations of islands and shoals. Such, for in- 
stance, are the Archipelago of Tierra del Fuego, the Lagulias 
Bank south of the Cape of Good Hope, and Van Diemen's 
Land, separated from New Holland by Bass's Straits. North- 
ern Asia extends to the above parallel at Cape Taimura, which, 
according to Krusenstern, is 78° 16', while it falls below it 
from the mouth of the Great Tschukotschja River eastward 
to Behring's Straits, in the eastern extremity of Asia — Cook's 
East Cape — which, according to Beechey, is only 66° S'.f 
The northern shore of the New Continent follows with toler- 
able exactness the parallel of 70°, since the lands to the north 
and south of Barrow's Strait, from Boothia Felix and Victoria 
Land, are merely detached islands. 

The pyramidal configuration of all the southern extremities 
of continents belongs to the similitudi7ies pliydcce in configii- 
ratione Qnundi, to which Bacon already called attention in his 
Novum Organon, and with which Reinhold Foster, one of 
Cook's companions in his second voyage of circumnavigation, 
connected some ingenious considerations. On looking eastward 
from the meridian of Tenerifie, we perceive that the southern 
extremities of the three continents, viz., Africa as the extreme 

* Strabo, lib. i., p. 65, Casaub. See Humboklt, Examen Crit., t. i. 
p. 152. 

f On the mean latitude of the Northern Asiatic shores, and the true 
name of Cape Taimura (Cape Siewero-Wostotschuoi), and C;ipe North- 
east (Schalagskoi Mys), see Humboldt, Asie Centrale. t, iii., p. 35. 37. 



PHYSICAL GEOGRAPHY. 291 

of the Old World, Australia, and South America, successively 
approach nearer toward the south pole. New Zealand, whose 
length extends fully 12*^ of latitude, forms an intermediate 
link between Australia and South America, likewise termina- 
ting in an island. New Leinster, It is also a remarkable cir- 
cumstance that the greatest extension toward the south falls 
in the Old Continent, under the same meridian in which the 
extremest projection toward the north pole is manifested. This 
will be perceived on comparing the Cape of Good Hope and 
the Lagullas Bank with the North Cape of Europe, and the 
peninsula of Malacca with Cape Taimura in Siberia.* We 
know not whether the poles of the earth are surrounded by 
land or by a sea of ice. Toward the north pole the parallel 
of 82^ 55' has been reached, but toward the south pole only 
that of 78^ 10'. 

The pyramidal terminations of the great continents are vari- 
ously repeated on a smaller scale, not only in the Indian Ocean, 
and in the peninsulas of Arabia, Hindostan, and Malacca, but 
also, as was remarked by Eratosthenes and Polybius, in the 
Mediterranean, where these writers had ingeniously compared 
together the forms of the Iberian, Italian, and Hellenic penin- 
sulas.! Europe, whose area is five times smaller than that 
of Asia, may almost be regarded as a multifariously articulated 
western peninsula of the more compact mass of the continent 
' of Asia, the climatic relations of the former being to those of 
the latter as the peninsula of Brittany is to the rest of France. t 
The influence exercised by the articulation and higher devel- 
opment of the form of a continent on the moral and intellect- 
ual condition of nations was remarked by Strabo,§ who extols 

* Humboldt, Asie Centrale, t. i., p. 198-200. The southern point 
of America, and the Archipelago which we call Terra del Fuego, lie in 
the meridian of the northwestern part of Baffin's Bay, and of the great 
polar land, whose limits have not as yet been ascertained, and which, 
perhaps, belongs to West Greenland. 

t Strabo, lib. ii., p. 92, 108, Casaub. 

X Humboldt, Asie Centrale, t. iii., p. 25. As early as the year 1817, 
in my work De distributione Geographicd Plantarum, secundum coeli 
temperiem, et altitndinem Mojitium, I directed attention to the import 
ant influence of compact and of deeply-articulated continents on climate 
and human civilization, " Regiones vel per sinus lunatos in longa cornua 
porrecta^, angulosis littorum recessibus quasi membratim discerptaR, vel 
spatia patentia in immensum, quorum littora uullis incisa angulis ambit 
sine anfractu oceanus" (p. 81, 182). On the relations of the extent of 
coast to the area of a continent (considered in some degree as a meas- 
ure of the accessibility of the interior), see the inquiries in Berghaus, 
Annalen der Erdkundc, bd. xii., 183.5, s. 430, and Physikal. Atlas, 1839 
No. iii , 8. 69. $ Strabo. lib. ii., p. 92, 198, Casaub. 



292 COSMOS. 

the varied form of our small continent as a special advantage. 
Africa* and South America, which manifest so great a resem- 
blance in their configuration, are also the two continents that 
exhibit the simplest littoral outlines. It is only the eastern 
shores of Asia, w^hich, broken as it were by the force of the 
currents of the oceanf [fractas ex cequore terras), exhibit a 
richly-variegated configuration, peninsulas and contiguous isl- 
ands alternating from the equator to 60° north latitude. 

Our Atlantic Ocean presents all the indications of a valley. 
It is as if a flow of eddying waters had been directed first to- 
ward the northeast, then toward the northwest, and back 
again to the northeast. The parallelism of the coasts north 
of 10° south latitude, the projecting and receding angles, the 
convexity of Brazil opposite to the Gulf of Guinea, that of 
Africa under the same parallel, with the Gulf of the Antilles, 
all favor this apparently speculative view.| In this Atlantic 
valley, as is almost every where the case in the configuration 
of large continental masses, coasts deeply indented, and rich 
in islands, are situated opposite to those possessing a different 
character. I long since drew attention to the geognostic im- 
portance of entering into a comparison of the western coast of 
Africa and of South America within the tropics. The deeply- 
curved indentation of the African continent at Fernando Po, 
4° 30' north latitude, is repeated on the coast of the Pacific 
at 18° 15' south latitude, between the Valley of Arica and 
the Morro de Juan Diaz, w^here the Peruvian coast suddenly 
changes the direction from south to north which it had previ- 
ously followed, and inclines to the northwest. This change 

* Of Africa, Pliny says (v. 1), "Nee alia pars terrarum pauciores re- 
cipit sinus." The small Indian peninsula on this side the Ganges pre- 
sents, in its triangular outline, a third analogous form. In ancient 
Greece there prevailed an opinion of the regular configuration of the 
dry land. There were four gulfs or bays, among which the Persian 
Gulf was placed in opposition to the Hyrcanian or Caspian Sea (Arrian, 
vii., 16; Plut., in vita Alexandri, cap. 44; Dionys. Perieg., v. 48 and 
630, p. 11, 38, Bernh.). These four bays and the isthmuses were, ac- 
cording to the optical fancies of Agesianax, supposed to be reflected in 
the moon (Plut., de Facie in Orbem Lunce, p. 921, 19). Respecting the 
terra quadrijida, or four divisions of the dry land, of which two lay 
north and two south of the equator, see Macrobius, Comm. in Somnium 
Scipionis, ii., 9. I have submitted this portion of the geography of the 
ancients, regarding which great confusion prevails, to a new and care- 
ful examination, in my Examen Crit. de V Hist, de la G^ogr., t. i., p. 
119, 145, 180-185, as also in Asie Centr., t. ii., p. 172-178. 

+ Fleurieu, in Voyage de Marchand autour du Monde, t. iv., p. 38-42. 

t Humboldt, in the Journal de Physiqve, liii., 1799, p. 33; and Rel. 
Hist., t. ii., p. 19; t. iii., p. 189, 198. 



PHYSICAL GEOGRAPHY. 293 

of direction extends in like manner to the chain of the Andes, 
which, is divided into two parallel branches, affecting not only 
the littoral portions,* but even the eastern Cordilleras. In 
the latter, civilization had its earliest seat in the South Amer- 
ican plateaux, where the small Alpine lake of Titicaca bathes 
the feet of the colossal mountains of Sorata and Illimani. 
Further to the south, from Valdivia and Chiloe (40° to 42° 
south latitude), through the Archipelago de los Cho?ios to 
Tei'ra del Fuego, we find repeated that singular configuration 
of fiords (a blending of narrow and deeply-indented bays), 
which in the Northern hemisphere characterizes the western 
shores of Norway and Scotland. 

These are the most general considerations suggested by the 
study of the upper surface of our planet with reference to the 
form of continents, and their expansion in a horizontal direc- 
tion. We have collected facts and brought forward some 
analogies of configuration in distant parts of the earth, but we 
do not venture to regard them as fixed laws of form. When 
the traveler on the declivity of an active volcano, as, for in- 
stance, of Vesuvius, examines the frequent partial elevations 
by which portions of the soil are often permanently upheaved 
several feet above their former level, either immediately pre- 
ceding or during the continuance of an eruption, thus forming 
roof-like or flattened summits, he is taught how accidental 
conditions in the expression of the force of subterranean va- 
pors, and in the resistance to be overcome, may modify the 
form and direction of the elevated portions. In this manner, 
feeble perturbations in the equilibrium of the internal elastic 
forces of our planet may have inclined them more to its north- 
ern than to its southern direction, and caused the continent 
in the eastern part of the globe to present a broad mass, whose 
major axis is almost parallel with the equator, while in the 
western and more oceanic part the southern extremity is ex- 
tremely narrow. 

Very little can be empirically determined regarding the 
causal connection of the phenomena of the formation of con- 
tinents, or of the analogies and contrasts presented by their 

* Humboldt, iu Pogijendorf's Annalen der Physilc, bd. xl., s. 171. 
On the remarkable fiord formation at the southeast end of America, see 
Darwin's Journal (^Narrative of the Voyages of the Adventure and Bea- 
gle, vol. iii.), 1839, p. 266. The parallelism of the two mountain chains 
is maintained from 5° south to 5*^ north latitude. The change in the 
direction of the coast at Arica appears to be in consequence of the al- 
tered course of the fissure, above which the Cordillera of the Andes 
has been upheaved. 



294 COSMOS. 

* 

configuration. All that we know regarding- this subject re- 
solves itself into this one point, that the active cause is sub- 
terranean ; that continents did not arise at once in the form 
they now present, but were, as we have already observed, in- 
creased by degrees by means of numerous oscillatory elevations 
and depressions of the soil, or were formed by the fusion of 
separate smaller continental masses. Their present form is, 
therefore, the result of two causes, which have exercised a con- 
secutive action the one on the other : the first is the expression 
of subterranean force, whose direction we term accidental, 
owing to our inability to define it, from its removal from with- 
in the sphere of our comprehension, while the second is derived 
from forces acting on the surface, among which volcanic erup- 
tions, the elevation of mountains, and currents of sea water 
play the principal parts. How totally difTerent would be the 
condition of the temperature of the earth, and, consequently, 
of the state of vegetation, husbandry, and human society, if 
the major axis of the New Continent had the same direction 
as that of the Old Continent ; if, for instance, the Cordilleras, 
instead of having a southern direction, inclined from east to 
west ; if there had been no radiating tropical continent, like 
Africa, to the south of Europe ; and if the Mediterranean, 
which was once connected with the Caspian and Red Seas, 
and which has become so powerful a means of furthering the 
intercommunication of nations, had never existed, or if it had 
been elevated like the plains of Lombardy and Cyrene 1 

The changes of the reciprocal relations of height between 
the fluid and solid portions of the earth's surface (changes 
which, at the same time, determine the outlines of continents, 
and the greater or lesser submersion of low lands) are to be 
ascribed to numerous unequally working causes. The most 
powerful have incontestably been the force of elastic vapors 
inclosed in the interior of the earth, the sudden change of tem- 
perature of certain dense strata,* the unequal secular loss of 

* De la Beclie, Sections and Views illustrative of Geological Phenome- 
na, 1830, tab. 40 ; Charles Babbage, Ohservations on the Temple of 
Serapis at Pozzuoli, near Naples, and on certain Causes which may 
produce Geological Cycles of great Extent, 1834. " If a stratum of sand- 
stone five miles in thickness should have its temperature raised about 
100°, its surface would rise twenty-five feet. Heated beds of clay 
would, on the contrary, occasion a sinking of the ground by their con- 
traction." See Bischof, Wdrmelehre des Innern unseres Erdkorpers, s. 
303, concerning the calculations for the secular elevation of Sweden, on 
the supposition of a rise by so small a quantity as 7° in a stratum of 
about 155,000 feet in thickness, and heated to a state of fusion. 



piiYS[('Ai. <;i',u(;kaimiv. 295 

heat experienced by the crust and nucleus ot" the earth, occa- 
pioning ridges in the sohd surface^ local modifications of gravi- 
tation,* and, as a consequence of" these alterations, in the curv- 
ature of a portion of the liquid element. According to the 
views generally adopted by geognosists in the present day, and 
w^hich are supported by the observation of a series of well- 
attested facts, no less than by analogy with the most import- 
ant volcanic phenomena, it would appear that the elevation 
of continents is actual, and not merely apparent or owing to 
the configuration of the upper surface of the sea. The merit 
of having advanced this view belongs to Leopold von Buch, 
who first made his opinions known to the scientific world in 
the narrative of his memorable Travels through Norway a?id 
Sweden in 1806 and I807.t While the whole coast of 
Sweden and Finland, from Solvitzborg, on the limits of North- 
ern Scania, past Gefle to Tornea, and from Tornea to Abo, 
experiences a gradual rise of four feet in a century, the south- 
ern part of Sweden is, according to Neilson, undergoing a 
simultaneous depression.:}: The maximum of this elevating 

* The opinion so iniplicitly entertained regarding the invariability of 
the force of gravity at any given point of the earth's surface, has in 
some degree been controverted by the gradual rise of large portions of 
the earth's surface. See Bessel, Ueber Maas mid Gewicht, in Schu- 
macher's Jahrbuch fur 1840, s. 134. 

+ Th. ii. (1810), s. 389. See Hallstroni, in Kongl. Vetenskaps-Aca- 
demiens Handlingar (Stockh-), 1823, p. 30; Lyell, in the Philos. TraTis. 
for 1835 ; Blom (Anitmann in Budskerud), Stat. Besckr. von Noricegen, 
1843, s. 89-116. If not before Von Buck's travels through Scandinavia, 
at any rate before their publication, Playfair, in 1802, in his illustrations 
of the Huttonian theory, § 393, and, according to Keilhau {Om Land- 
jordens Stigning in Norge, in the N^t Magazine fur Naturvidenska- 
berne), and the Dane Jessen, even before the time of Playfair, had ex- 
pressed the opinion that it was not the sea which was sinking, but the 
solid land of Sweden which was rising. Their ideas, however, were 
wholly unknown to our great geologist, and exerted no influence on 
the progi'ess of physical geography. Jessen, in his work, Kongeriget 
Norge fremstillet efter dels natui-lige eg borgerlige Tilstand, Kjobenh., 
1763, sought to explain the causes of the changes in the relative levels 
of the land and sea, basing his views on the early calculations of Celsius, 
Kalm, and Dalin. He broaches some confused ideas regarding the pos- 
sibility of an internal growth of rocks, but finally declares himself in 
favor of an upheaval of the land by earthquakes, "although," he ob- 
serves, " no" such rising was apparent immediately after the earthquake 
of Egersund, yet the earthquake may have opened the way for other 
causes producing such an etfect." 

X See Berzelius, Jakrsbericht uber die Fortschritte der Physischcn 
Wiss., No. 18, s. 686. The islands of Saltholm, opposite to Copen 
hageu, and Bjornholm, however, rise but very little — Bjornhohn scarce- 
ly one foot in a century See Forchhammer, in Philos. Magazine. Zd 
Series, vol, ii., p 309 



296 COSMOS. 

force appears to Lr in the north of Lapland, and to diminish 
gradually to the south toward Calmar and Solvitzborg. Lines 
marking the ancient level of the sea in pre-historic times are 
indicated throughout the whole of Norway,* from Cape Lin- 
desnaes to the extremity of the North Cape, by banks of shells 
identical with those of the present seas, and which have late- 
ly been most accurately examined by Bravais during his long 
winter sojourn at Bosekop. These banks lie nearly 650 feet 
above the present mean level of the sea, and reappear, accord- 
ing to Keilhau and Eugene Robert, in a north-northwest di- 
rection on the coasts of Spitzbergen, opposite the North Cape. 
Leopold von Buch, who was the first to draw attention to the 
high banks of shells at Tromsoe (latitude 69^ 40'), has, how- 
ever, shown that the more ancient elevations on the North 
Sea appertain to a different class of phenomena, from the 
regular and gradual retrogressive elevations of the Swedish 
shores in the Gulf of Bothnia. This latter phenomenon, which 
is well attested by historical evidence, must not be confound- 
ed with the changes in the level of the soil occasioned by 
earthquakes, as on the shores of Chili and of Cutch, and 
which have recently given occasion to similar observations in 
other countries. It has been found that a perceptible sinking 
resulting from a disturbance of the strata of the upper surface 
sometimes occurs, corresponding with an elevation elsewhere, 
as, for instance, in West Greenland, accordins: to Pino-el and 
Graah, in Dalmatia and in Scania. 

Since it is highly probable that the oscillatory movements 
of the soil, and the rising and sinking of the upper surface, 
were more strongly marked in the early periods of our planet 
than at present, we shall be less surprised to find in the inte- 
rior of continents some few portions of the earth's surface ly- 
ing below the general level of existing seas. Instances of this 
kind occur in the soda lakes described by General Andreossy, 
the small bitter lakes in the narrow Isthmus of Suez, the 
Caspian Sea, the Sea of Tiberias, and especially the Dead 
Sea.f The level of the water in the two last-named seas is 

* Keilhau, in Ni/t Mag. fur Naturvid., 1832, bd. i., p. 105-2.54; bd. 
ii., p. -57; Bravais, Sur les Lignes d^ancien Nweau de la Mer, 1843, p. 
15-40. See, also, Darwin, "on the Parallel Roads of Glen-Roy and 
Lochaber," in Philos. Trans, for 1839, p. 60. 

t Humboldt, Asie Centrale, t. ii., p. 319-324; t. iii., p. 549-551 
The depression of the Dead Sea has been successively determined by 
the barometrical measurements of Count Bertou, by the more careful 
ones ot Russegger, and by the trigonometrical survey of Lieutenant Sy- 
mond, oi the Royal Navy, who states that the difTerence of level be- 



PHYSICAL GEOGRAPHY. 297 

666 and 1312 feet below the level of the Mediterranean. If 
we could suddenly remove the alluvial soil which covers the 
rocky strata in many parts of the earth's surface, we should 
discover how great a portion of the rocky crust of the earth 
was then below the present level of the sea. The periodic, 
although irregularly alternating rise and fall of the water of 
the Caspian Sea, of which I have myself observed evident 
traces in the northern portions of its basin, appears to prove, ^ 
as do also the observations of Darwin on the coral seas,t that 
without earthquakes, properly so called, the surface of the 
earth is capable of the same gentle and progressive oscilla- 
tions as those which must have prevailed so generally in the 
earliest ages, when the surface of the hardening crust of the 
earth was less compact than at present. 
• The phenomena to which we would here direct attention 
remind us of the instability of the present order of things, and 
of the changes to which the outlines and configuration of con- 
tinents are probably still subject at long intervals of time. 
That which may scarcely be perceptible in one generation, 
accumulates during periods of time, whose duration is revealed 
to us by the movement of remote heavenly bodies. The east- 
ern coast of the Scandinavian peninsula has probably risen 

tween the surface of the Dead Sea and the highest houses of Jaffa is 
about 160.5 feet. Mr. Alderson, who communicated this result to the 
Geographical Society of London in a letter, of the contents of which I 
was informed by my friend, Captain Washington, was of opinion (Nov. 
28, 1841) that the Dead Sea lay about 1400 feet under the level of the 
Mediterranean. A more recent communication of Lieutenant Symond 
(Jameson's Edinburgh New Philosophical Journal, vol. xxxiv., 1843, p, 
178) gives 1312 feet as the final result of two very accordant trigono- 
metrical operations. 

* Sur la Mobility du fond de la Mer Caspienne, in my Asie Centr., t, 
ii., p. 283-294. The Imperial Academy of Sciences of St. Petersburgh. 
in 1830, at my request, charged the learned physicist Lenz to place 
marks indicating the mean level of the sea, for definite epochs, in dif- 
fei'ent places near Baku, in the peninsula of Abscheron. In the same 
manner, in an appendix to the instructions given to Captain (now Sir 
James C.) Ross for his Antarctic expedition, I m*ged the necessity of 
causing marks to be cut in the rocks of the southern hemisphere, as 
had already been done in Sweden and on the shores of the Caspian 
Sea. Had this measure been adopted in the early voyages of Bougain- 
ville and Cook, we should now know whether the secular relative 
changes in the level of the seas and land are to be considered as a gen- 
eral, or merely a local natural phenomenon, and whether a law of di 
rection can be recognized in the points which have simultaneous ele- 
vation or depression. 

t On the elevation and depression of the bottom of the South Sea, 
and the different areas of alternate movements, see Darwin's Journal, 
p. 557, 5G 1-566. 

N2 



298 COSMOS. 

about 320 feet in the space of 8000 years; and in 12,000 
years, if the movement be regular, parts of the bottom of the 
sea which He nearest the shores, and are in the present day 
covered by nearly fifty fathoms of vv^ater, will come to the 
surface and constitute dry land. But what are such intervals 
of time compared to the length of the geognostic periods re- 
vealed to us in the stratified series of formations, and in the 
world of extinct and varying organisms I We have hitherto 
only considered the phenomena of elevation ; but the analo- 
gies of observed facts lead us with equal justice to assume the 
possibility of the depression of whole tracts of land. The 
mean elevation of the non-mountainous parts of France 
amounts to less than 480 feet. It would not, therefore, re- 
quire any long period of time, compared with the old geog- 
nostic periods, in which such great changes were brought 
about in the interior of the earth, to effect the permanent 
submersion of the northwestern part of Europe, and induce 
essential alterations in its littoral relations. 

The depression and elevation of the solid or fluid parts of 
the earth — phenomena which are so opposite in their action 
that the efiect of elevation in one part is to produce an appar- 
ent depression in another — are the causes of all the changes 
which occur in the configuration of continents. In a work of 
this general character, and in an impartial exposition of the 
phenomena of nature, we must not overlook the possibility 
of a diminution of the quantity of water, and a constant de- 
pression of the level of seas. There can scarcely be a doubt 
that, at the period when the temperature of the surface of the 
earth was higher, when the waters were inclosed in larger 
and deeper fissures, and when the atmosphere possessed a to- 
tally different character from what it does at present, great 
changes must have occurred in the level of seas, depending 
upon the increase and decrease of the liquid parts of the 
earth's surface. But in the actual condition of our planet, 
there is no direct evidence of a real continuous increase or de- 
crease of the sea, and we have no proof of any gradual change 
in its level at certain definite points of "observation, as indi- 
cated by the mean range of the barometer. According to ex- 
periments made hy Daussy and Antonio Nobile, an increase 
in the height of the barometer would in itself be attended by 
a depression in the level of the sea. But as the mean press- 
ure of the atmosphere at the level of the sea is not the same 
at all latitudes, owing to meteorological causes depending upon 
the direction of the wind and varying degrees of moisture, the 



PHYSICAL GEOGRAniY. 299 

6arometer alone can not afford a certain evidence of the gen- 
2ral change of level in the ocean. The remarkable fact that 
«ome of the ports in the Mediterranean were repeatedly left 
dry during several hours at the beginning of this century, ap- 
pears to show that currents may, by changes occurring in 
their direction and force, occasion a local retreat of the sea, 
and a permanent drying of a small portion of the shore, with- 
out being followed by any actual diminution of water, or any 
permanent depression of the ocean. We must, however, be 
very cautious in applying the knowledge which we have late- 
ly arrived at, regarding these involved phenomena, since we 
might otherwise be led to ascribe to water, as the elder ele- 
ment, what ought to be referred to the two other elements, 
earth and air. 

As the external configuration of continents, which we have 
already described in their horizontal expansion, exercises, by 
their variously-indented littoral outlines, a favorable influence 
on climate, trade, and the progress of civilization, so likewise 
does their internal articulation, or the vertical elevation of 
the soil (chains of mountains and elevated plateaux), give rise 
to equally important results. Whatever produces a poly- 
morphic diversity of forms on the surface of our planetary 
habitation — such as mountains, lakes, grassy savannas, or 
even deserts encircled by a band of forests — impresses some 
peculiar character on the social condition of the inhabitants. 
Ridges of high land covered by snow impede intercourse ; but 
a blending of low, discontinued mountain chains* and tracts 
of valleys, as we see so happily presented in the west and 
south of Europe, tends to the multiplication of meteorological 
processes and the products of vegetation, and, from the variety 
manifested in different kinds of cultivation in each district, 
even under the same degree of latitude, gives rise to wants 
that stimulate the activity of the inhabitants. Thus the aw- 
ful revolutions, during which, by the action of the interior on 
the crust of the earth, great mountain chains have been ele- 
vated by the sudden upheaval of a portion of the oxydized 
exterior of our planet, have served, after the establishment 
of repose, and on the revival of organic life, to furnish a ricli- 
er and more beautiful variety of individual forms, and iii a 
great measure to remove from the earth that aspect of dreary 

* Humboldt, Rel. Hist., t. iii., p. 232-234. See, also, the able re- 
marks on the configuratiou of the earth, and the position of its Hues 
of elevation, in Albrechts von Roon, Grundzugen der Erd Volker und 
Staalenkvnde, Abth. i., 1837, s. 1.58, 270, 276. 



300 COSMOS. 

uniformity wliich exercises so impoverisliing an influence on 
the physical and intellectual powers of mankind. 

x\ccording to the grand views of Elie de Beaumont, we 
must ascribe a relative age to each system of mountain chains* 
on the supposition that their elevation must necessarily have 
occurred between the period of the deposition of the vertical- 
ly elevated strata and that of the horizontally inclined strata 
running at the base of the mountains. The ridges of the 
Earth's crust — elevations of strata which are of the same ge- 
ognostic age — appear, moreover, to follow one common direc- 
tion. The line of strike of the horizontal strata is not always 
parallel with the axis of the chain, but intersects it, so that, 
according to my views,! the phenomenon of elevation of the 
strata, which is even found to be repeated in the neighboring 
plains, must be more ancient than the elevation of the chain. 
The main direction of the whole continent of Europe (from 
southwest to northeast) is opposite to that of the great fissures 
which pass from northwest to southeast, from the mouths of 
the Rhine and Elbe, through the Adriatic and Red Seas, and 
through the mountain system of Putschi-Koh in Luristan, to- 
ward the Persian Gulf and the Indian Ocean. This almost 
rectangular intersection of geodesic lines exercises an import- 
ant influence on the commercial relations of Europe, Asia, 
and the northwest of Africa, and on the progress of civilization 
on the formerly more flourishing shores of the Mediterranean .J 

Since grand and lofty mountain chains so strongly excite 
our imagination by the evidence they aflbrd of great terres- 
trial revolutions, and when considered as the boundaries of 
climates, as lines of separation for waters, or as the site of a 
different form of vegetation, it is the more necessary to de- 
monstrate, by a correct numerical estimation of their volume, 
how small is the quantity of their elevated mass when com- 
pared with the area of the adjacent continents. The mass 
of the Pyrenees, for instance, the mean elevation of whose 
summits, and the areal quantity of whose base have been as- 
certained by accurate measurements, would, if scattered over 

* Leop. vou Buch, Ueber die Geognostischen Systems von Deutschland, 
ia his Geogn. Briefen an Alexander von Humboldt, 1824, s. 2G5-271; 
Klie de Beaumont, Recherches sur les Revolutions de la Swface du Globe, 
1829, p. 297-307. 

t Humboldt, Asie Centrale, t. i., p. 277-283. See, also, my Essai 
sur le Gisement des Roches, 1822, p. 57, and Relat. Hist., t. iii., p. 
244-250. 

X Asie Centrale, t. i., p. 284, 286. The Adriatic §ea likewise follows 
a direction from S.E. to N.W. 



PHYSICAL GEOGRAPHY. 301 

the surface of France, only raise its mean level about 115 
feet. The mass of the eastern and western Alps would in 
like manner only increase the height of Europe about 21|^ 
feet above its present level. I have found by a laborious in- 
vestigation,* which, from its nature, can only give a maximum 
limit, that the center of gravity of the volume of the land 
raised above the present level of the sea in Europe and North 
America is respectively situated at an elevation of 671 and 
748 feet, while it is at 1132 and 1152 feet in Asia and South 
America. These numbers show the low level of northern 
regions. In Asia the vast steppes of Siberia are compensated 
for by the great elevations of the land (between the Himalaya, 
the North Thibetian chain of Kuen-lun, and the Celestial 
Mountains), from 28° 30' to 40^ north latitude. We may, 
to a certain extent, trace in these numbers the portions of the 
Earth in which the Plutonic forces were most intensely mani- 
fested in the interior by the upheaval of continental masses. 

There are no reasons why these Plutonic forces may not, 
in future ages, add new mountain systems to those which Elie 
de Beaumont has shown to be of such different ages, and in- 
clined in such difierent directions. Why should the crust of 
the Earth have lost its property of being elevated in ridges ? 
The recently-elevated mountain systems of the xllps and the 
Cordilleras exhibit in Mont Blanc and Monte Rosa, in Sorata, 
Illimani, and Chimborazo, colossal elevations which do not 
favor the assumption of a decrease in the intensity of the sub- 
terranean forces. All geognostic phenomena indicate the 
periodic alternation of activity and repose ;t but the quiet 
we now enjoy is only apparent. The tremblings which still 
agitate the surface under all latitudes, and in every species of 
rock, the elevation of Sweden, the appearance of new islands 
of eruption, are all conclusive as to the unquiet condition of 
our planet. 

* De la hauteur Moyenne des Conlments, in my Asie Centrale, t. i., p. 
82-90, 165-189. The results which I have obtained are to be regard- 
ed as the extreme value {nombres-limites). Laplace's estinuile of the 
meau height of continents at 3280 feet is at least three times too high. 
The immortal author of the Mecanique Celeste (t. v., p. 14) \va.s led to 
this conclusion by hypothetical views as to the meau depth of the se:i. 
I have shown (Asie Centr., t. i., p. 93) that the old Alexandii;iu math- 
ematicians, on the testimony of Plutarch {in JEmilio Paulo, cap. 1.5), 
believed this depth to depend on the height of the mountains. Tlie 
height of the center of gravity of the volume of the continental masses 
is probably subject to slight variations in the course of many c.'!ntu:ie.s 

t Zioeiier Geologischer Brief von Elie de Beaumont an Alexander von 
Humboldt, in Poggendorf'.s Annalen, bd. xxv., s. 1-58. 



302 COSMOS. 

The two envelopes of the solid suriace of our planet — the 
liquid and the aeriform — ^exhibit, owing to the mobility of 
their particles, their currents, and their atmospheric relations, 
many analogies combined with the contrasts which arise from 
the great difference in the condition of their aggregation and 
elasticity. The depths of ocean and of air are alike unknown 
to us. At some few places under the tropics no bottom has 
been found with soundings of 276,000 feet (or more than four 
miles), while in the air, if, according to Wollaston, we may 
assume that it has a limit from which waves of sound may 
be reverberated, the phenomenon of twilight would incline 
us to assume a height at least nine times as great.* The 
aerial ocean rests partly on the solid earth, whose mountain 
chains and elevated plateaux rise, as we have already seen, 
like green wooded shoals, and partly on the sea, whose surface 
forms a moving base, on which rest the lower, denser, and 
more saturated strata of air. 

Proceeding: unward and downward from the common limit of 

Ox 

the aerial and liquid oceans, we fmd that the strata of air 
and water are subject to determinate laws of decrease oi" tem- 
perature. This decrease is much less rapid in the air than 
in the sea, which has a tendency under all latitudes to main- 
tain its temperature in the strata of "water most contiguous to 
the atmosphere, owing to the sinking of the heavier and more 
cooled particles. A large series of the most carefully con- 
ducted observations on temperature shows us that in the or- 
dinary and mean condition of its surface, the ocean from the 
equator to the forty-eighth degree of north and south latitude 
is somewhat warmer than the adjacent strata of air.f Owing 
to this decrease of temperature at increasing depths, fishes and 
other inhabitants of the sea, the nature of whose digestive and 
respiratory organs fits them for living in deep water, may even, 
under the tropics, find the low degree of temperature and the 
coolness of climate characteristic of more temperate and more 
northern latitudes. This circumstance, which is analogous- 
to the prevalence of a mild and even cold air on the elevated 
plains of the torrid zone, exercises a special influence on the 
migration and geographical distribution of many marine ani- 
mals. Moreover, the depths at wljich fishes live, modify, by 
the increase of pressure, their cutaneous respiration, and tlie 

* [See Wilson's Paper, Oa Wollastoii's Argument from the Limitati.m 
of the Atmosphere as to the finite Divisibility of Matter. — Trans, of the. 
Royal Society of Edinb., vol. xvi., p. 1, 1845.] — Tr. 

t Humboldt, Relation Hist., t. iii., chup. xxix., p. 514-530. 



PHYSICAL GEOGRAPHY. 303 

oxygenous and nitrogenous contents of their swimming blad- 
ders. 

As fresh and salt water do not attain the maximum of 
their density at the same degree of temperature, and as the 
saltness of the sea lowers the thermometrical degree corre- 
sponding to this point, we can understand how the watei 
drawn from great depths of the sea during the voyages of 
Kotzebue and Dupetit-Thouars could have been found to have 
only the temperature of 37^ and SG'^'O. This icy temperature 
of sea water, which is likewise manifested at the depths of 
tropical seas, first led to a study of the lower polar currents, 
which move from both poles toward the equator. Without 
these submarine currents, the tropical seas at those depths 
could only have a temperature equal to the local maximum 
of cold possessed by the falling particles of water at the radi- 
ating and cooled surface of the tropical sea. In the Mediter- 
ranean, the cause of the absence of such a refrigeration of the 
lower strata is ingeniously explained by Arago, on the as- 
sumption that the entrance of the deeper polar currents into 
the Straits of Gibraltar, where the water at the surface flows 
in from the Atlantic Ocean from west to east, is hindered by 
the submarine counter-currents which move from east to 
west, from the Mediterranean into the Atlantic. 

The ocean, which acts as a general equalizer and moder- 
ator of climates, exhibits a most remarkable uniformity and 
constancy of temperature, especially between 10° north and 
10° south latitude,* over spaces of many thousands of square 
miles, at a distance from land where it is not penetrated by 
currents of cold and heated water. It has, therefore, been 
justly observed, that an exact and long-continued investiga- 
tion of these thermic relations of the tropical seas might most 
easily afford a solution to the great and much-contested prob- 
lem of the permanence of climates and terrestrial tempera 
tures.t Great changes in the luminous disk of the sun would, 

* See the series of observations made by me in the South Sea, from 
0° 5' to 13° 16' N. lat., in my Asie Centrale, t. iii., p. 234. 

t " We might (by means of the temperature of the ocean under the 
tropics) enter into the consideration of a question which has hitherto 
remained unanswered, namely, that of the constancy of terrestrial tem 
peratures, without taking into account the very cii'cumscribed local 
influences arising from the diminution of wood in the plains and on 
mountains, and the drying up of lakes and marshes. Each age might 
easily transmit to the succeeding one some few data, which would per- 
haps furnish the most simple, exact, and direct means of deciding whetn- 
er the sun, which is almost the sole and exclusive source of the heat of 



304 C03M03. 

if they were of long duration, be reflected with more certainty 
in the mean temperature of the sea than in that of the solid 
land. 

The zones, at which occur the maxima of the oceanic tem- 
perature and of the density (the saline contents) of its waters, 
do not correspond with the equator. The two maxima are 
separated from one another, and the waters of the highest tem- 
perature appear to form two nearly parallel lines north and 
south of the geographical equator, Lenz, in his voyage of 
circumnavigation, found in the Pacific the maxima of density 
in 22° north and 17° south latitude, while its minimum was 
situated a few degrees to the south of the equator. In the 
region of calms the solar heat can exercise but little influence 
on evaporation, because the stratum of air impregnated with 
saline aqueous vapor, which rests on the surface of the sea, 
remains still and unchanged. 

The surface of all connected seas must be considered as 
having a general perfectly equal level with respect to their 
mean elevation. Local causes (probably prevaihng winds and 
currents) may, however, produce permanent, although trifling 
changes in the level of some deeply-indented bays, as, for in- 
stance, the Red Sea. The highest level of the water at the 
Isthmus of Suez is at different hours of the day from 24 to 
30 feet above that of the Mediterranean. The form of the 
Straits of Bab-el-Mandeb, through which the waters appeal 
to find an easier ingress than egress, seems to contribute to 
this remarkable phenomenon, which was known to the an- 
cients.* The admirable geodetic operations of Coraboeuf and 
Delcrois show that no perceptible difl^erence of level exists be- 
tween the upper surfaces of the Atlantic and the Mediterra- 
nean, along the chain of the Pyrenees, or between the coasts 
of northern Holland and Marseilles. t 

our planet, changes its physical constitution and splendor, like the great 
er number of the stars, or whether, on the contrary, that luminary has 
attained to a permanent condition." — Arago, in the Comptes Rendua 
des Siances de V Acad, des Sciences, t. xi., Part ii., p. 309. 

* Humboldt, Asie Centrale, t. ii., p. 321, 327. 

t See the numerical results in p. 328-333 of the volume just named 
From the geodesical levelings which, at my request, my frieud General 
Bolivar caused to be taken by Lloyd and Falmarc, in the years 1828 
and 1829, it was ascertained that the level of the Pacific is at the ut- 
most 3i feet higher than that of the Caribbean Sea; and even that at 
different hours of the day each of the seas is in turn the higher, accord- 
ing to their respective hours of flood and ebb. If we reflect that in a 
distauce of 64 miles, comprising 933 stations of observation, an error of 
three feet would be very apt to occur, we may say that in these new 



PHYSICAL GEOGRAPHY. 305 

Disturbances of equilibrium and consequent movements cf( 
the waters are partly irregular and transitory, dependent upon 
winds, and producing waves which sometimes, at a distance 
from the shore and during a storm, rise to a height of more 
than 35 feet ; partly regular and periodic, occasioned by the 
position and attraction of the sun and moon, as the ebb and 
flow of the tides ; and partly permanent, although less in- 
tense, occurring as oceanic currents. The phenomena of 
tides, which prevail in all seas (with the exception of the 
smaller ones that are completely closed in, and where the ebb- 
ing and flowing waves are scarcely or not at all perceptible), 
have been perfectly explained by the Newtonian doctrine, 
and thus brought " within the domain of necessary facts." 
Each of these periodically-recurring oscillations of the waters 
of the sea has a duration of somewhat more than half a day. 
Although in the open sea they scarcely attain an elevation of 
a few feet, they often rise considerably higher where the waves 
are opposed by the configuration of the shores, as, for instance, 
at St. Malo and in Nova Scotia, where they reach the re- 
spective elevations of 50 feet, and of 65 to 70 feet. " It has 
been shown by the analysis of the great geometrician La- 
place, that, supposing the depth to be wholly inconsiderable 
when compared with the radius of the earth, the stability of 
the equilibrium of the sea requires that the density of its fluid 
should be less than that of the earth ; and, as we have already 
seen, the earth's density is in fact five times greater than 
that of water. The elevated parts of the land can not there- 
fore be overflowed, nor can the remains of marine animals 
found on the summits of mountains have been conveyed to 
those localities by any previous high tides."* It is no slight 

operatious we have further confirmation of the equilibrium of the wa- 
ters which communicate round Cape Horn. (Arago, in the Annuaire 
du Bureau des Longitudes pour 1831, p. 319.) I had inferred, from 
barometrical observations instituted in 1799 and 1804, tliat if there were 
any diflference between the level of the Pacific and the Atlantic (Ca- 
ribbean Sea), it could not exceed three meters (nine feet three inches). 
See my Relat. Hist., t. iii., p. 555-557, and Annales de Chimie, t. i., 
p. 55-64. The measurements, which appear to establish an excess of 
height for the waters of the Gulf of Mexico, and for those of the nortli- 
ei'n part of the Adriatic Sea, obtained by combining the trigonometrical 
operations of Delcrois and Choppin with those of the Swiss and Aus- 
trian engineers, are open to many doubts. Notwithstanding tlie form 
of the Adriatic, it is improbable that the level of its waters in its north- 
ern portion should be 28 feet higher than that of the Mediterranean at 
Marseilles, and 25 feet higher than the level of the Atlantic Ocean- 
See my Asie Centrale, t. ii., p. 332. 
* Bessel, Ueber Flnth vnd Ebbc, in Schamachev^ ejahrbuch, 1838, s. 225 



806 COSMOS. 

evidence of the importance of analysis, which is too often re- 
garded with contempt among the unscientific, that Laplace's 
perfect theory of tides has enabled us, in our astronomical 
ephemerides, to predict the height of spring-tides at the peri- 
ods of new and full moon, and thus put the inhabitants of the 
sea-shore on their guard against the increased danger attend- 
ing these lunar revolutions. 

Oceanic currents, which exercise so important an influence 
on the intercourse of nations and on the climatic relations of 
adjacent coasts, depend conjointly upon various causes, differ- 
ing alike in nature and importance. Among these we may 
reckon the periods at which tides occur in their progress round 
the earth ; the duration and intensity of prevailing winds ; 
the modifications of density and specific gravity which the par- 
ticles of water undergo in consequence of differences in the 
temperature and in the relative quantity of saline contents at 
different latitudes and depths ;* and, lastly, the horary varia- 
tions of the atmospheric pressure, successively propagated from 
east to west, and occurring with such regularity in the trop- 
ics. These currents present a remarkable spectacle ; like riv- 
ers of uniform breadth, they cross the sea in different direc- 
tions, while the adjacent strata of water, which remain un- 
disturbed, form, as it were, the banks of these moving streams. 
This difference between the moving waters and those at rest 
is most strikingly manifested where long lines of sea- weed, 
borne onward by the current, enable us to estimate its veloc- 
ity. In the lower strata of the atmosphere, we may some- 
times, during a storm, observe similar phenomena in the lim- 
ited aerial current, which is indicated by a narrow line of 
trees, which are often found to be overthrown in the midst of 
a dense wood. 

The general movement of the sea from east to west be- 

* The relative density of the pai'ticles of water depends simultane- 
ously on the temperature and on the amount of the saline contents — a 
circumstance that is not sufficiently borne in mind in considering the 
cause of cun-ents. The submarine current, which brings the cold po- 
lar water to the equatorial regions, would follow an exactly opposite 
course, that is to say, from the equator toward the poles, if the ditfer- 
ence in saline contents were alone concerned. In this view, the geo- 
graphical distribution of temperature and of density in the water of 
the ocean, under the different zones of latitude and longitude, is of 
great importance. The numerous observations of Lenz (Poggeudorf's 
Annalen, bd. xx., 1830, s. 129), and those of Captain Beechey, collect- 
ed in his Voyage to the acijic, vol. ii., p. 727, deserve particular at- 
tention. See Humboldt, Relat. Hist., t. i., p. 74, and Asia Centrale, 
t. iii., p. 356, 



PHYSICAL GEOGRAPHy. 307 

tweeii the tropics (termed the equatorial or rotation current) 
is considered to be owing to the propagation ol' tides and to 
the trade winds, [ts direction is changed by the resistance 
it experiences from the prominent eastern shores of continents. 
The results recently obtained by Daussy regarding the veloc 
ity of this current, estimated from observations made on the 
distances traversed by bottles that had purposely been thrown 
into the sea, agree within one eighteenth with the velocity of 
motion (10 French nautical miles, 952 toises each, in 24 hours) 
which I had found from a comparison Avith earlier experi- 
ments.*' Christopher Columbus, during his third voyage, 
when he w-as seeking to enter the tropics in the meridian of 
Tenerifie, WTote in his journal as follows :t " I regard it as 
proved that the waters of the sea move from east to west, as 
do the heavens {las aguas van con los cielos), that is to say, 
like the apparent motion of the sun, moon, and stars." 

The narrow currents, or true oceanic rivers which traverse 
the sea, bring warm water into higher and cold water into 
lower latitudes. To the first class belongs the celebrated 
Gulf Stream, t which Avas known to Anghiera,§ and more 
especially to Sir Humphrey Gilbert in the sixteenth century. 
Its first impulse and origin is to be sought to the south of 
the Cape of Good Hope ; after a long circuit it pours itself 
from the Caribbean Sea and the Mexican Gulf throuffh the 
Straits of the Bahamas, and, following a course from south- 
southwest to north-northeast, continues to recede from the 
shores of the United States, until, further deflected to the 
eastward by the Banks of Newfoundland, it approaches the 
European coasts, frequently throwing a quantity of tropical 
seeds {Mimosa scandcns, Guilaiidina bonduc, Dolichos urens) 
on the shores of Ireland, the Hebrides, and Norway. The 
northeastern prolongation tends to mitigate the cold of the 
ocean, and to ameliorate the climate on the most northern ex- 
tremity of Scandinavia. At the point where the Gulf Stream 

* Humboldt, Relat. Hist., t. i., p. 64 ; Nouvelles Annales des Voyages, 
1839, p. 255. 

t Humboldt, Examen Crit. de VHist. de la Geogr., t. iii., p. 100. 
Cohimbus adds shortly after (Navarrete, Coleccio7i de los Viages y De- 
scubrimientos d-e los Espanoles, t. i., p. SCO), that the movement i.s 
strongest in the Caribbean Sea. In i'act, Rennell terms this region, 
" not a current, but a sea in motion" {Investigation of Currents, p. 23). 

X Humboldt, Examen Critique, t. ii., p. 250; Relat. Hist., t. i., p. 
66-74. 

§ Petrtis Martyr de Angliiera, De Rebus Oceanicis et Orbe Novo, 
Bas., I.r23, Dec. iii., lib. vi., p. 57. See Humboldt, Examen Critique, 
t. ii,, p. J ) 4-257, and t, iii.. p. 108. 



308 COSMOS. 

is deflected from the Banks of Newfoundland toward the east, 
it sends oiF branches to the south near the Azores.* This is 
the situation of the Sargasso Sea, or that great bank of weeds 
which so vividly occupied the imagination of Christopher Co- 
lumbus, and which Oviedo calls the sea- weed meadows [Pra- 
derias de yerva). A host of small marine animals inhabits 
these gently-moved and evergreen masses of Fiicus natans, 
one of the most generally distributed of the social plants of 
the sea. 

The counterpart of this current (which in the Atlantic 
Ocean, between Africa, America, and Europe, belongs almost 
exclusively to the northern hemisphere) is to be found in the 
South Pacific, where a current prevails, the effect of whose low 
temperature on the climate of the adjacent shores I had an 
opportunity of observing in the autumn of 1802. It brings 
the cold waters of the high southern latitudes to the coast of 
Chili, follows the shores of this continent and of Peru, first from 
south to north, and is then deflected from the Bay of Arica on- 
ward from south-southeast to north-northwest. At certain 
seasons of the year the temperature of this cold oceanic cur- 
rent is, in the tropics, only 60°, while the undisturbed adjacent 
water exhibits a temperature of 810-5 and SS*^-?. On that 
part of the shore of South America south of Payta, which in- 
clines furthest westward, the current is suddenly deflected in 
the same direction from the shore, turning so sharply to the 
west that a ship sailing northward passes suddenly from cold 
into warm water. 

It is not known to what depth cold and warm oceanic cur- 
rents propagate their motion ; but the deflection experienced 
by the South African current, from the Lagullas Bank, which 
is fully from 70 to 80 fathoms deep, would seem to imply the 
existence of a far-extending propagation. Sand banks and 
shoals lying beyond the line of these currents may, as was first 
discovered by the admirable Benjamin Franklin, be recognized 
by the coldness of the water over them. This depression of 
the temperature appears to me to depend upon the fact that, 
by the propagation of the motion of the sea, deep waters rise 
to the margin of the banks and mix with the upper strata. 
My lamented friend. Sir Humphrey Davy, ascribed this phe- 
nomenon (the knowledge of which is often of great practical 
utility in securing the safety of the navigator) to the descent 
of the particles of water that had been cooled by nocturnal ra- 

* Humboldt, Examen Crit., t. iii., p. G4-109. 



PHYSICAL GEOGRAPHY. 309 

diation, and which remain nearer to the surface, owing to the 
hinderance placed in the way of their greater descent by the 
intervention of sand-banks. By his observations Frankhn may 
be said to have converted the thermometer into a soundinjj 
line. Mists are frequently found to rest over these depths, ow- 
ing to the condensation of the vapor of the atmosphere by the 
cooled waters. I have seen such mists in the south of Jamai- 
ca, and also in the Pacific, defining with sharpness and clear- 
ness the form of the shoals below them, appearing to the eye 
as the aerial reflection of the bottom of the sea. A still more 
striking eflect of the cooling produced by shoals is manifested 
in the higher strata of air, in a somewhat analogous manner 
to that observed in the case of flat coral reefs, or sand islands 
In the open sea, far from the land, and when the air is calm, 
clouds are often observed to rest over the spots where shoals 
are situated, and their bearing may then be taken by the com- 
pass in the same manner as that of a high mountain or isola- 
ted peak. 

Although the surface of the ocean is less rich in livingf forms 
than that of continents, it is not improbable that, on a further 
investigation of its depths, its interior may be found to possess 
a greater richness of organic life than any other portion of our 
planet. Charles Darwin, in the agreeable narrative of his ex- 
tensive voyages, justly remarks that our forests do not conceal 
so many animals as the low woody regions of the ocean, where 
the sea- weed, rooted to the bottom of the shoals, and the sev- 
ered branches of fuci, loosened by the force of the waves and 
currents, and swimming free, imfbld their delicate foliage, up- 
borne by air-cells.* The application of the microscope increas- 
es, in the most striking manner, our impression of the rich lux- 
uriance of animal life in the oceaii, and reveals to the aston- 
ished senses a consciousness of the universality of life. In the 
oceanic depths, far exceeding the height of our loftiest mount- 
ain chains, every stratum of water is animated with polygas- 
tric sea- worms, Cyclidise, and Ophrydinaj. The waters swarm 
with countless hosts of small luminiferous animalcules, Mam- 
maria(of the order of Acalephse), Crustacea, Peridinea, and cir- 
cling Nereides, which, when attracted to the surface by peculiar 
meteorological conditions, convert every v/ave into a foaming 
band of flashing light. 

* [See Structure and Distribution of Coral Reefs, hy Charles Darwiu, 
London, 1842. Also, Narrative of the Surveying Voyage of H.M.S. 
" Fly^^ in the Eastern Archipelago, during the Years 1842-184G, by J. 
B. Jukes, Naturalist to the expedition, 1847.] — Tr. 



310 COSMOS. 

The abundance of these marine anhnalcules, and the anima* 
matter yielded by their rapid decomjjosition, are so vast that 
the sea water itself becomes a nutrient fluid to many of tho 
larger animals. However much this richness in animated 
forms, and this multitude of the most various and highly-de- 
veloped microscopic organisms may agreeably excite the fancy, 
the imagination is even more seriously, and, I m^ight say, more 
solemnly moved by the impression of boundlessness and im- 
measurability, which are presented to the mind by every sea 
voyage. All who possess an ordinary degree of mental activi- 
ty, and delight to create to themselves an inner world of 
thought, must be penetrated with the sublime image of the 
infinite when gazing around them on the vast and boundless 
sea, when involuntarily the glance is attracted to the distant 
horizon, where air and water blend together, and the stars con- 
tinually rise and set before the eyes of the mariner. This con- 
templation of the eternal play of the elements is clouded, like 
every human joy, by a touch of sadness and of longing. 

A peculiar predilection for the sea, and a grateful remem- 
brance of the impression which it has excited in my mind, when 
I have seen it in the tropics in the calm of nocturnal rest, or 
in the fury of the tempest, have alone induced me to speak of 
the individual enjoyment afibrded by its aspect before I en- 
tered upon the consideration of the favorable influence which 
the proximity of the ocean has incontrovertibly exercised on 
the cultivation of the intellect and character of many nations, 
by the multiplication of those bands which ought to encircle 
the whole of humanity, by affording additional means of arriv- 
ing at a knowledge of the configuration of the earth, and fur- 
thering the advancement of astronomy, and of all other math- 
ematical and physical sciences. A portion of this influence 
was at first limited to the Mediterranean and the shores of 
southwestern Africa, but from the sixteenth century it has 
wddely spread, extending to nations who live at a distance 
from the sea, in the interior of continents. Since Columbus 
was sent to " unchain the ocean"* (as the unknown voice 
whispered to him in a dream when he lay on a sick-bed near 

* The voice addressed him iu these words, " Maravillosamente Dios 
liizo sonar tu nombre en la tieiTa ; de los atamientos de la mar Oceana, 
que estaban cerrados con cadenas tan tuertes, te dio las Haves" — " God 
will cause thy name to be wonderfully resounded through the earth, 
and give thee the keys of the gates of the ocean, which are closed with 
strong chains." The dream of Columbus is related in the letter to the 
Catholic monarchs of July the 7th, 1503. (Humboldt, Exavien CrUiqis.e, 
L iii. p. 234.) 



METEOROLOGY, 311 

the River Belem), man has ever boldly ventured onward to- 
ward the discovery of unknown regions. 

The second external and general covering of our planet, the 
aerial ocean, in the lower strata, and on the shoals of which 
we live, presents six classes of natural phenomena, which man- 
ifest the most intimate connection wTth one another. They 
are dependent on the chemical composition of the atmosphere, 
the variations in its transparency, polarization, and color, its 
density or pressure, its temperature and humidity, and its elec- 
tricity. The air contains in oxygen the first element of phys-" 
ical animal life, and, besides this benefit, it possesses another, 
which may be said to be of a nearly equally high character, 
namely, that of convejdng sound ; a faculty by which it like- 
wise becomes the conveyer of speech and the means of com- 
municating thought, and, consequently, of maintaining social 
intercourse. If the Earth were deprived of an atmosphere, as 
we suppose our moon to be, it would present itself to our im- 
agination as a soundless desert. 

The relative quantities of the substances composing the 
strata of air accessible to us have, since the beginning of the 
nineteenth century, become the object of investigations, in 
which Gay-Lussac and myself have taken an active part ; it 
is, however, only very recently that the admirable labors of 
Dumas and Boussingault have, by new and more accurate 
methods, brought the chemical analysis of the atmosphere to 
a high degree of perfection. According to this analysis, a 
volume of dry air contains 20 8 of oxygen and 79-2 of nitro- 
gen, besides from two to five thousandth parts of carbonic 
acid gas, a still smaller quantity of carbureted hydrogen gas,* 
and, according to the important experiments of Saussure and 
Liebig, traces of ammoniacal vapors,t from which plants de- 
rive their nitrogenous contents. Some observations of Lewy 
render it probable that the quantity of oxygen varies percep- 

* Boussingault, Recherches sur la Composition de V Atmosphere, in thd 
Annales de Chimie et de Physique, t. Ivii., 1834, p. 171-173; and Ix.xi. 
1839, p. IIG. According to Boussingault and Lewy, the pioportiun of 
carbonic acid in tlie atmosphere at Audilly, at a distance, therefore, from 
the exhalations of a city, varied only between 000028 and 0-00031 hi 
vokime. " 

+ Liebig, lu his important work, entitled Die Organische Chemie in 
ihrer Anwendung auf Agricultur und Physiologic, 1840, s. G2-7'2. On 
the influence of atmospheric electricity in the production of nitrut;- of 
ammonia, which, coming into contact with carbonate of lime, is changed 
into carbonate of ammonia, see Boussingault's Economic Rurale con- 
sidiric dans ses Rapports avec la Chimie et la M6t6orologie, 184 1, t. ii., 
p. 247,267, and t. i., p. 84. 



312 COSMOS. 

tibly, although but sHghtly, over the sea and in the interior 
of continents, according to local conditions or to the seasons of 
the year. We may easily conceive that changes in the oxy- 
gen held in solution in the sea, produced by microscopic an- 
imal organisms, may be.attended by alterations in the strata 
of air in immediate contact with it.* The air which Martins 
collected at Faulhorn at an elevation of 8767 feet, contained 
as much oxygen as the air at Paris. f 

The admixture of carbonate of ammonia in the atmosphere 
may probably be considered as older than the existence of or- 
ganic beings on the surface of the earth. The sources from 
which carbonic acid$ may be yielded to the atmosphere are 
most numerous. In the first place we would mention the res- 
piration of animals, who receive the carbon which they inhale 
from vegetable food, while vegetables receive it from the at- 
mosphere ; in the next place, carbon is supplied from the in- 
terior of the earth in the vicinity of exhausted volcanoes and 
thermal springs, from the decomposition of a small quantity of 
carbureted hydrogen gas in the atmosphere, and from the elec- 
tric discharges of clouds, which are of such frequent occurrence 
within the tropics. Besides these substances, which we have 
considered as appertaining to the atmosphere at all heights 
that are accessible to us, there are others accidentally mixed 
with them, especially near the ground, which sometimes, in 
the form of miasmatic and gaseous contagia, exercise a noxious 
influence on animal organization. Their chemical nature has 
not yet been ascertained by direct analysis ; but, from the con- 
sideration of the processes of decay which are perpetually go- 
ing on in the animal and vegetable substances with which the 
surface of our planet is covered, and judging from analogies 
deduced from the domain of pathology, we are led to infer the 
existence of such noxious local admixtures. Ammoniacal and 
other nitrogenous vapors, sulphureted hydrogen gas, and com- 
pounds analogous to the polybasic ternary and quaternary com- 
binations of the vegetable kingdom, may produce miasmata,^ 

* Lewy, in the Comptes Rendus de VAcad. des Sciences, t. xvii., Part 
ii., p. 235-248. 

t Dumas, in the Annates de Chimie, 3e Sirie, t. iii., 1841, p. 257. 

t In this enumeration, the exhalation of carbonic acid by plants dur- 
ing the night, while they inhale oxygen, is not taken into account, be- 
cause the increase of carbonic acid from this source is amply counter- 
balanced by the respiratory process of plants during the day. See Bous- 
singault's Econ. Rurale, t. i., p. 53-68, and Liebig's Organische Chemie, 
B. 16, 21. 

$ Gay-Lussac, in Annates de Chimie, t. liii., p. 120 ; Payen, M6m. sut 



METEOROLOGY 313 

which, under various forms, may generate ague and typhus 
fever (not by any means exclusively on wet, marshy ground, 
or on coasts covered by putrescent moUusca, and low bushes 
of Rhizo'phoTa moMgle and Avicennia). Fogs, w^hich have 
a peculiar smell at some seasons of the year, remind us of 
these accidental admixtures in the lower strata of the atmos- 
phere. Winds and currents of air caused by the heating of 
the ground even carry up to a considerable elevation solid 
substances reduced to a fine powder. The dust which dark- 
ens the air for an extended area, and falls on the Cape Verd 
Islands, to which Darwin has drawn attention, contains, ac- 
cording to Ehrenberg's discovery, a host of silicious-shelled in 
fusoria. 

As principal features of a general descriptive picture of the 
atmosphere, we may enumerate : 

1 . Variations of atmospheric pressure : to which belong 
the horary oscillations, occurring with such regularity in the 
tropics, \vhere they produce a kind of ebb and flow in the at- 
mosphere, wdiich can not be ascribed to the attraction of the 
moon,^ and which differs so considerably according to geo- 
graphical latitude, the seasons of the year, and the elevation 
above the level of the sea. 

2. Climatic distribution of heat, which depends on the 
relative position of the transparent and opaque masses (the 
fluid and solid parts of the surface of the earth), and on the 
hypsometrical configuration of continents ; relations which de- 
termine the geographical position and curvature of the iso- 
thermal lines (or curves of equal mean annual temperature) 
both in a horizontal and vertical direction, or on a uniform 
plane, or in difierent superposed strata of air. 

3. The distribution of the humidity of the atmosphere. 
The quantitative relations of the humidity depend on the dif- 
ferences in the solid and oceanic surfaces ; on the distance from 
the equator and the level of the sea ; on the form in which the 

la ComposUion Chimi'que des Vegetaux, p. 36, 42 ; Liebig, Org. Cheinic. 
s. 229-3-15; Boussiugaiilt, Eco7i. Rurale, t. i., p. 142-153. 

* Boavard, by the application of the formula), iu 1827, whicli La[)l:«ce 
had deposited with the Board of Longitude shortly before his death, 
found that the portion of the horary oscillations of the pressure of the 
atmosphere, which depends on the attraction of the moon, can not raise 
the mercury in the barometer at Paris more than the 0-018 of a milli- 
meter, while eleven years' observations at the same place show the nieau 
barometric oscillation, from 9 A.M. to 3 P.M.. to be 0756 millim., and 
from 3 P.M. to 9 P.M., 0-373 millim. See M6moires de VAcad. des 
Sciences, t. vii., 1827, p. 267. 

Vol. I.— O • 



311 COSxMOS. 

aqueous vapor is precipitated, and on tlie connection existing 
between these deposits and the chanijes of temperature, and 
the direction and succession of Avinds. 

4. Tlie electric condition of the atmosphere. The primary 
cause of this condition, when the heavens are serene, is still 
much contested. Under this head we must consider the re- 
lation of ascending- vapors to the electric charge and the form 
of the clouds, according to the different periods of the day and 
year ; the difference between the cold and warm zones of the 
earth, or low and high lands ; the frequency or rarity of thun- 
der storms, their periodicity and formation in summer and 
winter ; the causal connection of electricity, with the infre- 
quent occurrence of hail in the night, and with the phe- 
nomena of water and sand spouts, so ably investigated by 
Peltier. 

The horary oscillations of the barometer, which in the trop- 
ics present two maxima (viz., at 9 or 9J- A.M., and 10^ or 
105 P.M., and two minima, at 4 or 41 P.M., and" 4 A.M., 
occurring, therefore, in almost the hottest and coldest hours), 
have long been the object of my most careful diurnal and noc- 
turnal observations.* Their regularity is so great, that, in 
the daytime especially, the hour may be ascertained from the 
height of the mercurial column without an error, on the av- 
erage, of more than fifteen or seventeen minutes. In the tor- 
rid zones of the New Continent, on the coasts as well as at 
elevations of nearly 13,000 feet above the level of the sea, 
where the mean temperature falls to 44°-6, I have found the 
regularity of the ebb and flow of the aerial ocean undisturbed 
by storms, hurricanes, rain, and earthquakes. The amount 
of the daily oscillations diminishes from 1*32 to 0'18 French 
lines from the equator to 70^ north latitude, where Bravais 
made very accurate observations at Bosekop.f The supposi- 
tion that, much nearer the pole, the height of the barometer 
is really less at 10 A.M. than at 4 P.M., and, consequently, 
that the maximum and minimum influences of these hours 

* Observations faites four conslater la Marche des Variations Horaires 
dn Barometre sotis les Tropiques, in iny Relation Historique die Voyage, 
aux Regions Equinoxiales, t. iii., p. 270-31.3. 

t Bravais, in Kaerntz and Martins, Meleorologie, p. 263. A*^. Halhi 
(ol*^ 29' N. lat.), the oscillation still amounts to 0-28 lines. It would 
seem that a great many observations will be required in oider to obfiiin 
re.sults that can be trusted in regard to the hours of the maximum and 
minimum on mountains in the temperate zone. See the nb^^ervationa 
of horary variations, collected on the Faulhurn in 1832, 1841, aiid l?>\t 
(Martin?. MHeorologie. p. 25-i.) 



ATMOSPHERIC PRESSURE. 315 

are inverted, is not confirmed by Parry's observations at Port 
Bowen (73° 14'). 

The mean height of the barometer is somewhat less under 
the equator and in the tropics, ov\^ing to the effect of the rising 
current,* than in the temperate zones, and it appears to attain 
its maximum in Western Europe between the parallels of 40° 
and 45°. If with Kilmtz we connect together by isobaromet- 
ric lines those places which present the same mean difference 
between the monthly extremes of the barometer, we shall have 
curves whose geographical position and inflections yield im- 
portant conclusions regarding the influence exercised by the 
form of the land and the distribution of seas on the oscillations 
of the atmosphere. Hindostan, with its high mountain chains 
and triangular peninsulas, and the eastern coasts of the New 
Continent, where the warm Gulf Stream turns to the east at 
the Newfoundland Banks, exhibit greater isobarometric oscil- 
lations than do the group of the Antilles and Western Europe. 
The prevailing winds exercise a principal influence on the 
diminution of the pressure of the atmosphere, and this, as we 
have already mentioned, is accompanied, according to-Daussy, 
by an elevation of the mean level of the sea.t 

As the most important fluctuations of the pressure of the 
atmosphere, whether occurring with horary or annual regu- 
larity, or accidentally, and then often attended by violence and 
danger,! are, like all the other phenomena of the weather, 
mainly owing to the heating force of the sun's rays, it has 
long been suggested (partly according to the idea of Lambert) 
that the direction of the wind should be compared with the 
height of the barometer, alternations of temperature, and the 
increase and decrease of humidity. Tables of atmospheric 
pressure during different winds, termed barometric ivi7idroses. 
afford a deeper insight into the connection of meteorological 
phenomena.^ Dove has, with admirable sagacity, recognized, 
in the " law of rotation" in both hemispheres, w^iich he him- 
self established, the cause of many important processes in the 
aerial ocean. || The difference of temperature between the 

* Humboldt, Essai sur la Geographic des Planles, 1807, p. 90; .lud 
ia ReL Hist., t. iii., p. 313 ; and on the diuiinutiou of atmospheric press- 
ure ill the tropical portions of the Atlantic, in Poggeud.. Annalen dcr 
Physik, bd. xxxvii., s. 245-258, and s. 468-486. 

t Daussy, in the Comptes Rendits, t. iii., p. 136. 

X Dove, Ueber die Sturme, in Poggend., Aniialen, bd. Iii., s. 1. 

^ Leopold von Buch, Baromelrische Windrose, in Ahhandl. dcr AJcad. 
der Wiss. zu Berlin aus den Jahren 18 1 8- IS 19, s. 187. 

il See Dove, Meteorologische Untersuchnngen. 1837, s. '""^313; aiiJ 



316 COiMOS. 

equatorial and polar regions engenders two opposite currents 
in the upper strata ol the atmosphere and on the Earth's sur- 
face. Owing to the difference between the rotatory velocity 
at the poles and at the equator, the polar current is deflected 
eastward, and the equatorial current westward. The great 
phenomena of atmospheric pressure, the warming and cooling 
of the strata of air, the aqueous deposits, and even, as Dove 
has correctly represented, the formation and appearance of 
clouds, alike depend on the opposition of these two currents, 
on the place where the upper one descends, and on the dis- 
placement of the one by the other. Thus the figures of the 
clouds, which form an animated part of the charms of a land- 
scape, announce the processes at work in the upper regions of 
the atmosphere, and, when the air is calm, the clouds will 
often present, on a bright summer sky, the " projected image" 
of the radiating soil below. 

Where this influence of radiation is modified by the relative 
position of large continental and oceanic surfaces, as between 
the eastern shore of Africa and the western part of the Indian 
peninsula, its effects are manifested in the Indian monsoons, 
which change with the periodic variations in the sun's decli- 
nation,* and which were known to the Greek navigators un- 
der the name of Hipjoalos. In the knowledge of the mon- 
soons, which undoubtedly dates back thousands of years among 
the inhabitants of Hindostan and China, of the eastern parts 
of the Arabian Gulf and of the western shores of the Malayan 

the excellent observations of Kamtz on the descent of the west wind 
of the upper current in high latitudes, and the general phenomena of 
the direction of the wind, in his Vorlesungen uber Melerologie, 1840, s. 
58-66, 196-200, 327-336, 353-364; and in ^chnrndichev' s Jahrhuch fur 
1838, s. 291-302. A very satisfactory and vivid representation of me- 
teorological phenomena is given by Dove, in his small work entitled 
Witterungsveihdltnisse von Berlin, 1842. On the knowledge of the 
earlier navigators of the rotation of the wind, see Churruca, Viage al 
Magellanes, 1793, p. 15 ; and on a remarkable expression of Columbus, 
which his son Don Fernando Colon has presented to us in his Vida del 
Almiranie, cap. 55, see Humboldt, Examen Critique de V Hist, de G6- 
ographie, t. iv., p. 253. 

* Monsun (Malayan musim, the hippalos of the Greeks) is derived 
from the Arabic word mausim, a set time or season of the yeaj", the time 
of the assemblage of pilgrims at Mecca. The word has been applied 
to the seasons at which certain winds prevail, which are, besides, named 
from places lying in the direction from whence they come ; thus, for 
instance, there is the mausim. of Aden, of Guzerat, Malabar, &c. (Las- 
sen, Indische Alterthumskunde, bd. i., 1843, s. 211). On the contrasts 
between the solid or fluid substrata of the atmosphere, see Dove, in Der 
Abhandl. der Akad. der Wiss. zu Berlin aus dem Jahr 1842, s. 239 



CLIMATOLOGY. 317 

Sea, and in the still more ancient and more general acouaint- 
ance with land and sea winds, lies concealed, as it were, the 
germ of that meteorological science which is now making such 
rapid progress. The long chain of magnetic stations extend- 
ing from Moscow to Pekin, across the whole of Northern Asia, 
will prove of immense importance in determining the law of 
the tvinds, since these stations have also for their object the 
investigation of general meteorological relations. The com- 
parison of observations made at places lying so many hundred 
miles apart, will decide, for instance, whether the same east 
wind blows from the elevated desert of Gobi to the interior of 
Russia, or whether the direction of the aerial current first be- 
gan in the middle of the series of the stations, by the descent 
of the air from the higher regions. By means of such observ- 
ations, we may learn, in the strictest sense, tche?ice the wind 
Cometh. If we only take the results on which we may de- 
pend from those places in which the observations on the direc- 
tion of the winds have been continued more than twenty years, 
we shall liud (from the most recent and careful calculations 
of Wilhelm Mahlmann) that in the middle latitudes of the 
temperate zone, in both continents, the prevailing aerial cur- 
rent has a west-southwest direction. 

Our insight into the distribution of heat in the atm.osphere 
has been rendered more clear since the attempt has been made 
to connect together by lines those places where the mean an- 
nual summer and winter temperatures have been ascertained 
by correct observations. The system of isothermal, isotheral^ 
and isochimenal lines, which I first brought into use in 1817, 
may, perhaps, if it be gradually perfected by the united efforts 
of investigators, serve as one of the main foundations o[ com- 
jMrative climatology. Terrestrial magnetism did not acquire 
a right to be regarded as a science until partial results were 
graphically connected in a system of lines of equal declina- 
tion, equal inclination, and equcd intensity. 

The term climate, taken in its most general sense, indicalos 
all the changes in the atmosphere which sensibly aflect our 
organs, as temperature, humidity, variations iu the baromei- 
rical pressure, the calm state of the air or the action ol' oup-'- 
site winds, the amount of electric tension, the purity ol' tlic 
atmosphere or its admixture with more or less noxious gase- 
ous exhalations, and, finally, the degree of ordinary transpui-- 
ency and clearness of the sky, which is not only important 
with respect to the increased radiation from tlu' Earth, the 
organic development of plants, and the ripening of fruits, but 



318 COSMOS. 

also with reference to its influence on the feelings and mental 
condition of men. 

If the surface of the Earth consisted of one and the same 
homogeneous fluid mass, or of strata of rock having the same 
color, density, smoothness, and power of absorbing heat from 
the solar ra3^s, and of radiating it in a similar manner through 
the atmosphere, the isothermal, isotheral, and isochimenal 
lines would all be parallel to the equator. In this hypothet- 
ical condition of the Earth's surface, the power of absorbing 
and emitting light and heat would every where be the same 
under the same latitudes. The mathematical consideration 
of climate, which does not exclude the supposition of the ex- 
istence of currents of heat in the interior, or in the external 
crust of the earth, nor of the propagation of heat by atmos- 
pheric currents, proceeds from this mean, and, as it were, 
primitive condition. Whatever alters the capacity for ab- 
sorption and radiation, at places lying under the same parallel 
of latitude, gives rise to inflections in the isothermal lines. 
The nature of these inflections, the angles at which the iso- 
thermal, isotheral, or isochimenal lines intersect the parallels 
of latitude, their convexity or concavity with respect to the 
pole of the same hemisphere, are dependent on causes which 
more or less modify the temperature under difTerent degrees 
of longitude. 

The progress of Climatology has been remarkably favored 
by the extension of European civilization to two opposite 
coasts, by its transmission from our western shores to a conti- 
nent which is bounded on the east by the Atlantic Ocean. 
When, after the ephemeral colonization from Iceland and 
Greenland, the British laid the foundation of the first perma- 
nent settlements on the shores of the United States of Amer- 
ica, the emigrants (whose numbers were rapidly increased in 
consequence either of religious persecution, fanaticism, or love 
of freedom, and who soon spread over the vast extent of ter- 
ritory lying between the Carolinas, Virginia, and the St. Law- 
rence) were astonished to find themselves exposed to an intens- 
ity of winter cold far exceeding that which prevailed in Ita- 
ly, France, and Scotland, situated in corresponding parallels 
of latitude. But, however much a consideration of these cli- 
matic relations may have awakened attention, it was not at- 
tended by any practical results until it could be based on the 
numerical data of mean annual temperature. If, between 
58^^ and 30*^ north latitude, we compare Nain, on the coast 
of Labrador, with Gottenburg ; Hahfax with Bordeaux ; New 



CIJMATOLOGY. 319 

V^ork with Naples ; St. Augustine, in Florida, with Cairo, we 
find that, under the same degrees of latitude, the differences 
of the mean annual temperature between Eastern America 
and Western Europe, proceeding from north to south, are suc- 
cessively 20O-7, 130-9, 60-8, and almost QO. The gradual 
decrease of the differences in this series extending over 28*^ 
of latitude is very striking. Further to the south, under the 
tropics, the isothermal lines are every where parallel to the 
equator in both hemispheres. We see, from the above exam- 
ples, that the questions often asked in society, how many de- 
grees America (without distinguishing between the eastern 
and western shores) is colder than Europe ? and how much 
the mean annual temperature of Canada and the United 
States is lower than that of corresponding latitudes in Eu- 
rope ? are, when thus generally exiiressed, devoid of meaning. 
Tiiere is a separate difference for each parallel of latitude, and 
without a special comparison of the winter and summer tem- 
peratures of the opposite coasts, it will be impossible to arrive 
at a correct idea of climatic relations, in their influence on 
agriculture and other industrial pursuits, or on the individual 
comfort or discomfort of mankind in general. 

In enumerating the causes which produce disturbances in 
the form of the isothermal lines, I would distinguish between 
those which raue and those which lower the temperature. 
To the first class belong the proximity of a western coast in 
the temperate zone ; the divided configuration of a continent 
into peninsulas, with deeply-indented bays and inland seas ; 
the aspect or the position of a portion of the land with refer- 
ence either to a sea of ice spreading far into the polar circle, 
or to a mass of continental land of considerable extent. Iving 
in the same meridian, either under the equator, or, at least, 
within a portion of the tropical zone ; the prevalence of south- 
erly or westerly winds on the western shore of a continent in 
the temperate northern zone ; chains of mountains acting as 
protecting walls against winds coming from colder regions ; 
the iufrequeney of sM'^amps, Avhich, in the s])ring and begin- 
ning of summer, long remain covered with ice, and tJie ab- 
sence of woods in a dry, sandy soil ; finally, the cou.stant se- 
renity of the sky in the summer months, and the vicinity of 
an oceanic current, bringing water which is of a higher tem- 
perature than that of the surrounding sea. 

Among the causes which tend to lower the mean ainiual 
temperature I include the following ; elevation above the level 
of the sea, when not forming part of an extended jiiain ; the 



320 COSMOS. 

vicinity of an eastern coast in high and middle latitudes ; the 
compact configuration of a continent having no littoral curv- 
atures or bays ; the extension of land toward the poles into 
the region of perpetual ice, without the intervention of a sea 
remaining open in the winter ; a geographical position, in 
which the equatorial and tropical regions are occupied by the 
sea, and, consequently, the absence, under the same meridian, 
of a continental tropical land having a strong capacity for the 
absorption and radiation of heat ; mountain chains, whose 
mural form and direction impede the access of warm winds , 
the vicinity of isolated peaks, occasioning the descent of cold 
currents of air down their declivities ; extensive woods, which 
hinder the insolation of the soil by the vital activity of theii 
foliage, which produces great evaporation, owing to the ex- 
tension of these organs, and increases the surface that is cool- 
ed by radiation, acting consequently in a three-fold manner, 
by shade, evaporation, and radiation ; the frequency of swamps 
or marshes, which in the north form a kind of subterranean 
glacier in the plains, lasting till the middle of the summer ; a 
cloudy summer sky, which weakens the action of the solar 
rays ; and, finally, a very clear winter sky, favoring the radi- 
ation of heat.* 

The simultaneous action of these disturbing causes, wheth- 
er productive of an increase or decrease of heat, determines, 
as the total effect, the inflection of the isothermal lines, espe- 
cially with relation to the expansion and configuration of solid 
continental masses, as compared with the liquid oceanic. 
These perturbations give rise to convex and concave summits 
of the isothermal curves. There are, however, different or- 
ders of disturbing causes, and each one must, therefore, be 
considered separately, in order that their total effect may aft- 
erward be investigated with reference to the motion (direc- 
tion, local curvature) of the isothermal lines, and the actions 
by which they are connected together, modified, destroyed, or 
increased in intensity, as manifested in the contact and inter- 
section of small oscillatory movements. Such is the method 
by which, I hope, it may some day be possible to connect to- 
gether, by empirical and numerically expressed laws, vast se- 
ries of apparently isolated facts, and to exhibit the mutual de- 
pendence which must necessarily exist among them. 

The trade winds — easterly winds blowing within the trop- 
ics — give rise, in both temperate zones, to the west, or west- 

* HamLokit, Recherches sur les Causes des Inflexions des Lignes Iso- 
thermes, in A.sie Centr., t. iii., p. 103-114, 118, 122, 188- 



CLIMATOLOGY. 321 

southwest winds which prevail in those regions, and which 
are land winds to eastern coasts, and sea winds to western 
coasts, extending over a space which, from the great mass 
and the sinking of its cooled particles, is not capable of any 
considerable degree of cooling, and hence it follows that the 
east winds of the Continent must be cooler than the west 
winds, where their temperature is not aflected by the occur- 
rence of oceanic currents near the shore. Cook's young com- 
panion on his second voyage of circumnavigation, the intelli- 
gent George Forster, to whom I am indebted for the lively 
interest which prompted me to undertake distant travels, was 
the first who drew attention, in a definite manner, to the cli- 
matic difi^erences of temperature existing in the eastern and 
western coasts of both continents, and to the similarity of 
temperature of the western coast of North America in the 
middle latitudes, with that of Western Europe.* Even in 
northern latitudes exact observations show a striking differ- 
ence between the mean aniiual temperaUire of the east and 
w^est coasts of America. The mean annual temperature of 
Nain, in Labrador (lat. 57*^ 10'), is fully 60-8 below the freez- 
ing point, while on the northwest coast, at New Archangel, 
in Russian America (lat. 57^ 3'), it is 12*^-4 above this point. 
At the first-named place, the mean summer temperature 
hardly amounts to 43°, while at the latter place it is 57^. 
Pekin (oQ*^ 54'), on the eastern coast of Asia, has a mean an- 
nual temperature of 52° -3, which is 9° below that of Naples, 
situated somewhat further to the north. The mean winter 
temperature of Pekin is at least 5° "4 below the freezing point, 
while in Western Europe, even at Paris (48° 50'), it is near- 
ly 6° above the freezing point. Pekin has also a mean win- 
ter cold which is 4° -5 lower than that of Copenhagen, lying 
17° further to the north. 

We have already seen the slowness with which the great 
mass of the ocean follows the variations of temperature in the 
atmosphere, and how the sea acts in equalizing temperatures, 
moderating simultaneously the severity of winter and the heat 
of summer. Hence arises a second more important contrast 
— that, namely, between insular and littoral climates enjoyed 
by all articulated continents having deeply-indented bays and 
peninsulas, and between the climate of the interior of great 
masses of solid land. This remarkable contrast has been fully 

* George Forster, Kleine Schriften, th. iii., 1794, s. 87 ; Dove, in 
Schumacher's Jahrbuch fur 1841, s. 289; Kamtz, Meteorologie, bd. ii., 
8. 41. 43, &7 , and 96 ; Arago, in the Comptes Rendus, t. i., p. 268. 

02 



322 COSMOS. 

developed by Leopold von Buch in all its various phenomena, 
both with respect to its influence on vegetation and agricul- 
ture, on the transparency of the atmosphere, the radiation of 
the soil, and the elevation of the line of perpetual snow. In 
the interior of the Asiatic Continent, Tobolsk, Barnaul on the 
Oby, and Irkutsk, have the same mean summer heat as Ber- 
lin, Munster, and Cherbourg in Normandy, the thermometer 
sometimes remaining for weeks together at 86° or 88°, while 
the mean winter temperature is, during the coldest month, as 
low as — 0°*4 to — 4°. These continental climates have 
therefore justly been termed excessive by the great mathema- 
tician and physicist Buffon ; and the inhabitants who live in 
countries having such excessive climates seem almost con- 
demned, as Dante expresses himself, 

" A sofFerir tormeuti caldi e geli."* 

In no portion of the earth, neither in the Canary Islands, 
in Spain, nor in the south of France, have I ever seen more 
luxuriant fruit, especially grapes, than in Astrachan, near the 
shores of the Caspian Sea (46° 21'). Although the mean 
annual temperature is about 48°, the mean summer heat 
rises to 70°, as at Bordeaux, while not only there, but also 
further to the south, as at Kislar on the mouth of the Terek 
(in the latitude of Avignon and Rimini), the thermometer 
sinks in the winter to — 13° or — 22°. 

Ireland, Guernsey, and Jersey, the peninsula of Brittany, 
the coasts of Normandy, and of the south of England, present, 
by the mildness of their winters, and by the low temperature 
and clouded sky of their summers, the most striking contrast 
to the continental climate of the interior of Eastern Europe, 
In the northeast of Ireland (54° 56'), lying under the same par- 
allel of latitude as Konigsberg in Prussia, the myrtle blooms 
as luxuriantly as in Portugal. The mean temperature of the 
month of August, which in Hungary rises to 70^, scarcely 
reaches 61° at Dublin, which is situated on the same isother- 
mal line of 49° ; the mean winter temperature, which falls to 
about 28° at Pesth, is 40° at Dublin (whose mean annual 
temperature is not more than 49°) ; 3°'6 higher than that of 
Milan, Pavia, Padua, and the whole of Lombardy, where the 
mean annual temperature is upward of 55 '. At Stromness, 
in the Orkneys, scarcely half a degree further south than Stock- 
holm, the winter temperature is 39°, and consequently iiighei 
^han that of Paris, and nearly as high as that of London. 

* Dante, Divina Commedia. Purgatorio, cauto iii. 



CLIMATOLOGY. 323 

Even in the Faroe Islands, at 62"^ latitude, the inland waters 
never freeze, owing to the favoring influence of the west winds 
and of the sea. On the charming coasts of Devonshire, near 
Salcombe Bay, which has been termed, on account of the 
mildness of its climate, the Moiitpelliej' of the North, the 
Agave Mexicana has been seen to blossom in the open air, 
while orange-trees trained against espaliers, and only slightly 
protected hy matting, are found to bear fruit. There, as well 
as at Penzance and Gosport, and at Cherbourg on the coast 
of Normandy, the mean winter temperature exceeds 42^, fall- 
ing short by only 2^*4 of the mean winter temperature of 
Montpellier and Florence.* These observations will suffice 
to show the important influence exercised on vegetation and 
agriculture, on the cultivation of fruit, and on the comfort of 
mankind, by differences in the distribution of the same mean 
annual temperature, through the different seasons of the year. 
The lines which I have termed isochimenal and isotheral 
(lines of equal winter and equal summer temperature) are by 
no means parallel with the isothermal lines (lines of equal 
annual temperature). If, for instance, in countries where 
myrtles grow wild, and the earth does not remain covered 
with snow in the winter, the temperature of the summer and 
autumn is barely sufficient to bring apples to perfect ripeness, 
and if, again, we observe that the grape rarely attains the 
ripeness necessary to convert it into wine, either in islands or 
in the vicinity of the sea, even when cultivated on a western 
coast, the reason must not be sought only in the low degree 
of summer heat, indicated, in littoral situations, by the ther- 
mometer when suspended in the shade, but likewise in another 
cause that has not hitherto been sufficiently considered, al- 
though it exercises an active influence on many other phe- 
nomena (as, for instance, in the inflammation of a mixture of 
chlorine and hydrogen), namely, the difTerence between direct 
and diffused light, or that which prevails when the sky is clear 
and when it is overcast by mist. I long since endeavored to 
attract the attention of physicists and physiologisisi to this 

* Humboldt, Sur lesLignes Isothermes, iu the Memoircs dc Ph//siqiie 
n de Chimie de la Societe d'' Arcueil, t. iii., Paris, 1817, [>. 1 1.3-1 ()•> ; 
Knight, in the Transactions of the HorticuUural Society of London, vol. 
, p. 32 ; Watson, Remarks on the Geographical Distribution of British 
Plants, 1835, p. 60; Trevelyan, in Jamieson's Edijihurgh Nefo Phil. 
Journal, No. 18. p. 154; Mahlmann, in his admirable Gerni.iu Tiaanila 
lion of my Asia Centrale, th. ii., s. 60. 

t *' HiKC de temperie aei-is, qui terram late circumfundit, ac in quo, 
longe a solo, instniinenta nostra meteorologica suspensa habemus. Sed 



324 COSMOS. 

difference, and to the %i7WieasuTed heat which is locally devel- 
oped in the living vegetable cell by the action of direct light. 
If, in forming a thermic scale of different kinds of cultiva- 
tion,* we begin with those plants which require the hottest 
climate, as the vanilla, the cacao, banana, and cocoa-nut, and 
proceed to pine-apples, the sugar-cane, coffee, frait-bearing 
date-trees, the cotton-tree, citrons, olives, edible chestnuts, and 
vines producing potable wine, an exact geographical consider- 
ation of the limits of cultivation, both on plains and on the 
declivities of mountains, will teach us that other climatic re- 
lations besides those of mean annual temperature are involved 
in these phenomena. Taking an example, for instance, from 
the cultivation of the vine, we find that, in order to procure 
■potable wine,t it is requisite that the mean annual heat should 
exceed 49*^, that the winter temperature should be upward of 
33"^, and the mean summer temperature upward of 64*^. At 
Bordeaux, in the valley of the Garonne (44° 50' lat.), the 
mean annual, winter, summer, and autumn temperatures are 
respectively 57°, 43°, 71°, and 58°. In the plains near the 

alia est caloi'is vis, quem radii solis nuUis nubibus velati, in foliis ipsis 
et fructibus maturescentibus, magis miiiusve coloratis, gignunt, quem- 
que, ut egregia demonstrant experimenta amicissiraorum Gay-Lussacii 
et Thenardi de combustione chlori et hydrogeuis, ope tbermometri me- 
tiri nequis. Etenim locis planis et moutanis, vento libe spirante, cir- 
cumfusi aeris temperies eadem esse potest coelo sudo vel nebuloso ; ide- 
uqu8 ex observationibus solis therraometricis, nullo adhibito Photome- 
tro, baud, cognosces, quam ob causam Gallise septentrioualis tractus 
Ai'moricanus et Nervicus, versus littora, coelo temperato sed sole raro 
utentia, Vitem fere non tolerant. Egent enim stirpes non solum caloris 
fitimulo, sed et lucis, quae magis intensa locis excelsis quam planis, du- 
plici modo plantas raovet, vi sua turn propria, tum calorem in supei'ficie 
earum excitante." — Humboldt, De Distributione Geographica Planta- 
riim, 1817, p. 163-164. 

* Humboldt, op. cit., p. 156-161; Meyen, in his Grtmdriss der 
PfianzengeograpMe, 1836, s. 379-467 ; Boussingault, Economic Rurale, 
t. ii., p. 675. 

t The following table illustrates the cultivation of the vine in Europe, 
and also the depreciation of its produce according to climatic relations. 
See ray Asie Centrale, t. iii., p. 159. The examples quoted in the text 
for Bordeaux and Potsdam are, in respect of numerical relation, alike 
applicable to the countnes of the Rhine and. Maine (48^^ 35' to 50° 7' 
N. lat.). Cherbourg in Normandy, and Ireland, show in the most re- 
mai'kable manner how, with thermal relations very nearly similar to 
those prevailing in the interior of the Continent (as estimated by tlie 
thermometer in the shade), the results are nevertheless extremely dif- 
ferent as regards the ripeness or the unripeness of the fruit of the vine, 
this difference undoubtedly depending on the circumstance whether 
the vegetation of the plant^proceeds under a bright sunny sky, o" un 
<ler a sky that is habitually obscurer] by clnnds: 



I 



CLIMATOLOGY. 



325 



Baltic (52^ 30' lat.), where a wine is produced that can 
scarcely be considered potable, these numbers are as follows : 
47'^0, 31°, 630-7, and 47'^-o. If it should appear strange 
that the great differences indicated by the influence of climate 
on the production of wine should not be more clearly manifest- 
ed by our thermometers, the circumstance will appear less 
singular when we remember that a thermometer standing in 
the shade, and protected from the effect of direct insolation 
and nocturnal radiation can not, at all seasons of the year, and 
during all periodic changes of heat, indicate the true superficial 
temperature of the ground exposed to the whole effect of the 
sun's rays. 

The same relations which exist between the equable littoral 
climate of the peninsula of Brittany, and the lower winter and 



Places. 


Latitude. 


Elevation. 


Mean 
of the 
Year. 


Winter. 


Spring. 


Summer. 


Autumn. 


Number of the 
Years of the 
Observation. 


Bordeaux . . . 


o / 

44 50 


Ens- ft. 

25-6 


Fahr. 

57-0 


43-0 


56-0 


71-0 


58-0 


10 


Strasbourg. . . 


48 35 


479-0 


49-6 


34-5 


50-0 


64-6 


50-0 


35 


Heidelberg. . 


49 24 


333-5 


49-5 


34-0 


50-0 


64-3 


49-7 


20 


Mauheitn . . . 


49 29 


300-5 


50-6 


34-6 


50-8 


67-1 


49-5 


12 


Wurzburg. . . 


49 48 


562-5 


50-2 


35-5 


50-5 


65-7 


49-4 


27 


Frankfort on 


















Maine .... 


50 7 


388-5 


49-5 


33-3 


50-0 


64-4 


49-4 I 19 


Berlin 


52 31 


102-3 


47-5 


31-0 


46-6 


63-6 


47-5 23 


Cherbourg (no 


49 39 


.... 


52-1 


41-5 


50-8 


61-7 


54-3 3 


wine) 
















Dublin (ditto) 


53 23 


.... 


49-1 


40-2 


47-1 


59-6 


49-7 13 



The great accordance in the distribution of the annual temperature 
through the different seasons, as presented by the results obtained for 
the valleys of the Rhine and Maine, tends to confirm the accuracy of 
these meteorological observations. The months of December, January, 
and February are reckoned as winter months. When the different 
qualities of the wines produced in Franconia, and in the countries 
around the Baltic, are compared with the mean summer and autumn 
temperature of Wilrzburg and Berlin, we are almost surprised to find 
a difference of only about two degrees. The difference in the spring 
is about four degrees. The influence of late May frosts on the flower- 
ing season, and after a coi-respondingly cold winter, is almost as iiii 
portant an element as the time of the subsequent ripening of the grape, 
and the influence of direct, not diffused, light of the unclouded sun 
The difference alluded to in the text between the true temperature of 
the surface of the ground and the indications of a thermometer sus 
pended in the shade and protected from extraneous influences, is in 
ierred by Dove from a consideration of the results of fifteen years' ob 
servations made at the Chiswick Gardens. See Dove, in Bericht i'lhe^ 
die Verhandl. der Berl. Akad. der Wisa., August, 1844, s. 285. 



326 COSMOS. 

higher summer temperature of the remainder of the continent 
of France, are Kkewise manifested, in some degree, between 
Europe and the great continent of Asia, of which the former 
may be considered to constitute the western peninsula. Eu- 
rope owes its milder climate, in the first place, to its position 
with respect to Africa, whose wide extent of tropical land is 
favorable to the ascending current, while the equatorial region 
to the south of Asia is almost wholly oceanic ; and next to its 
deeply-articulated configuration, to the vicinity of the ocean 
on its western shores ; and, lastly, to the existence of an open 
sea, which bounds its northern confines. Europe would there- 
fore become colder* if Africa were to be overflowed by the 
ocean ; or ii" the mythical Atlantis Avere to arise and connect 
Europe with North America ; or if the Gulf Stream were no 
longer to diffuse the warming influence of its waters into the 
North Sea ; or if, finally, another mass of solid land should be 
upheaved by volcanic action, and interposed between the 
Scandinavian peninsula and Spitzbergen, If we observe that 
in Europe the mean annual temperature falls as we proceed, 
from west to east, under the same parallel of latitude, from 
the Atlantic shores of France through Germany, Poland, and 
Russia, toward the Uralian Mountains, the main cause of this 
phenomenon of increasing cold must be sought in the form of 
the continent (which becomes less indented, and wider, and 
more compact as we advance), in the increasing distance from 
seas, and in the diminished influence of westerly winds. Be- 
yond the Uralian Mountains these winds are converted into 
cool land-winds, blowing over extended tracts covered with 
ice and snow. The cold of western Siberia is to be ascribed 
to these relations of configuration and atmospheric currents, 
and not — as Hippocrates and Trogus Pompeius, and even cele- 
brated travelers of the eighteenth century conjectured — to the 
great elevation of the soil above the level of the sea.f 

If we pass from the differences of temperature manifested in 
the plains to the inequalities ol' the polyhedric form of the sur- 
Iftce of our planet, we shall have to consider mountains either 
in relation to their influence on the climate of neighboring 

* See my memoir, Ueber die Haupt-Ursachen der Temperaturver- 
schiedenheii auf der Erdoberjldche, iu the Abhandl. der Akad. der Wis- 
sensch. zu Berlin von dem Jahr 1827, s. 311. 

t The general level of Siberia, from Tobolsk, Tomsk, and Barnaul, 
from the Altai Mountains to the Polar Sea, is not so hiijh as tliat of 
Manheim and Dresden ; indeed, Irkutsk, far to the east of the Jenisei, 
is only 1330 feet above the level of the sea, or about one third lowei 
than Munich. 



*.. 



CLIMATOLOGY. 327 



valleys, or according to the effects of the hypsometrical rela- 
lioiis on their own summits, which often spread into elevated 
p-.vU M.-ix. The division ol' mountains into chains separates 
iitc earth's surface into different basins, which are often nar 
rov,- iind walled in, forming caldron-like valleys, and (as in 
G iv;cce and in part of Asia Minor) constitute an individual 
local climate with respect to heat, moisture, transparency of 
atmosphere, and frequency of winds and storms. These cir- 
cumstances have at all times exercised a powerful influence 
on the character and cultivation of natural products, and on 
the manners and institutions of neighboring nations, and even 
on the feelings with which they regard one another. This 
character of geographical individuality attains its maximum, 
if we may be allowed so to speak, in countries where the dif- 
ferences in the configuration of the soil are the greatest possi- 
ble, either in a vertical or horizontal direction, both in relief 
and in the articulation of the continent. The greatest con- 
trast to these varieties in the relations of the surface of the 
earth are manifested in the Steppes of Northern Asia, the 
grassy plains (savannahs, llanos, and pampas) of the New 
Continent, the heaths {Ey'iceta) of Europe, and the sandy and 
stony deserts of Africa. 

The law of the decrease of heat with the increase of eleva- 
tion at different latitudes is one of the most important subjects 
involved in the study of meteorological processes, of the geog- 
raphy of plants, of the theory of terrestrial refraction, and of 
the various hypotheses that relate to the determination of the 
height of the atmosphere. In the many mountain journeys 
which I have undertaken, both within and without the trop- 
ics, the investigation of this law has always formed a special 
object of my researches.* 

Since we have acquired a more accurate knowledge of the 
true relations of the distribution of heat on the surface of the 
earth, that is to say, of the inflections of isothermal and isoth- 
eral lines, and their unequal distance apart in the different 
eastern and western systems of temperature in Asia, Central 
Europe, and North America, we can no longer ask the gen- 
eral question, what fraction of the mean annual or summer 
temperature corresponds to the difference of one degree of 
geographical latitude, taken in the same meridian ? In each 
system of isothermal lines of equal curvature there reigns a 

* Humboldt, Recueil d' Observations Astronomiques, t. i., p. 126-140; 
Relation Historiquc, t. i., p. 119, 141, 227; Biot, in Connaissance des 
Temps pour Van 1841, p. 90-109. 



328 COSMOS. 

close and necessary connection-between three elements, name 
ly, the decrease of heat in a vertical direction from below up 
ward, the difference of temperature for every one degree of 
geographical latitude, and the uniformity in the mean tem- 
perature of a mountain station, and the latitude of a point- 
situated at the level of the sea. 

In the system of Eastern America, the mean annual temper- 
ature from the coast of Labrador to Boston changes l°-6 foi 
every degree of latitude ; from Boston to Charleston about 
1°"7 ; from Charleston to the tropic of Cancer, in Cuba, the 
variation is less rapid, being only l°-2. In the tropics this 
diminution is so much greater, that from the Havana to 
Cumana the variation is less than 0°"4 lor every degree of 
latitude. 

The case is quite different in the isothermal system of Cen- 
tral Europe. Between the parallels of 38° and 71° I found 
that the decrease of temperature was very regularly 0°-9 fbi 
every degree of latitude. But as, on the other hand, in Cen- 
tral Europe the decrease of heat is 1°;8 for about every 534 
feet of vertical elevation, it follows that a diilerence of eleva- 
tion of about 267 feet corresponds to the diiTerence of one de- 
gree of latitude. The same mean annual temperature as that 
occurring at the Convent of St. Bernard, at an elevation of 
8173 feet, in lat. 45° 50', should therefore be met with at the 
level of the sea in lat. 75° 50'. 

In that part of the Cordilleras which falls within the tropics, 
the observations I made at various heights, at an elevation of 
upward of 19,000 feet, gave a decrease of 1° for every 341 
feet ; and my friend Boussingault found, thirty years after- 
ward, as a mean result, 319 feet. By a comparison of places 
in the Cordilleras, lying at an equal elevation above the level 
of the sea, either on the declivities of the mountains or even 
on extensive elevated plateaux, I observed that in the latter 
there was an increase in the animal temperature varying from 
2°*7 to 4°*1. This difference would be still greater if it were 
not for the cooling eftect of nocturnal radiation. As the dif- 
ferent climates are arranged in successive strata, the one above 
the other, from the cacao woods of the valleys to the region 
of perpetual snow, and as the temperature in the tropics va- 
ries but little throughout the year, we may form to ourselves 
a tolerably correct representation of the climatic relations to 
which the inhabitants of the large cities in the Andes are sub- 
jected, by comparing these climates with the temperatures of 
pavtioular months in the plains of France and Italy. While 



THE SNOW-LINE. 329 

the heat which prevails daily on the woody shores of the 
Orinoco exceeds hy 7^'2 that of the month of August at Pa- 
lermo, we find, on ascending the chain of the Andes, at Po- 
payan, at an elevation of 582G feet, the temperature of the 
three summer months of Marseilles ; at Quito, at an eleva- 
tion of 9541 feet, that of the close of May at Paris ; and on 
the Paramos, at a height of 11,510 feet, where only stunted 
Alpine shrubs grow, though flowers still bloom in abund- 
ance, that of the beginning of April at Paris. The intelligent 
observer, Peter Martyr de Anghiera, one of the friends of 
Christopher Columbus, seems to have been the first who rec- 
ognized (in the expedition undertaken by Rodrigo Enrique 
Colmenares, in October, 1510) that the limit of perpetual 
snow continues to ascend as we approach the equator. We 
read, in the fine work De Rebus Oceanicis,^ " the River Gaira 
comes from a mountain in the Sierra Nevada de Santa Marta,, 
which, according to the testimony of the companions of Col- 
menares, is higher than any other mountain hitherto discov- 
ered. It must undoubtedly be so if it retain S7ioiv perpet- 
ually in a zone which is not more than 10° from the equi- 
noctial line." The lower limit of perpetual snow, in a given 
latitude, is the lowest line at which snow continues durino- 
summer, or, in other words, it is the maximum of height to 
which the snow-line recedes in the course of the year. But 
this elevation must be distinguished from three othey phe- 
nomena, namely, the annual fluctuation of the snow-line, the 
occurrence of sporadic falls of snow, and the existence of gla- 
ciers, which appear to be peculiar to the temperate and cold 
zones. This last phenomenon, since Saussure's immortal 
work on the Alps, has received much light, in recent times, 
from the labors of Venetz, Charpentier, and the intrepid and 
persevering observer Agassiz. 

We know only the lower, and not the upper limit of per- 
petual snow ; for the mountains of the earth do not attain to 
those ethereal regions of the rarefied and dry strata of air, in 
which we may suppose, with Bouguer, that the vesicles of 
aqueous vapor are converted into crystals of ice, and thus ren- 
dered perceptible to our organs of sight. The lower limit of 
snow is not, however, a mere function of geographical latitude 
or of mean annual temperature ; nor is it at the equator, or 

* Anglerius, Ve Rebus Oceanicis, Dec. xi., lib. ii., p. 140 (ed. Col., 
1574). In the Sierra de Santa Marta, the highest point of which ap- 
pears to exceed 19,000 feet (see my R€lat. Hist., t. ii., p. 214), there is 
a peak that is still called Fico de Gaira. 



330 COSMOS. 

even in the region of the tropics, that this limit attains its 
greatest elevation above the level of" the sea. The phenome- 
non ot" which we are treating is extremely complicated, de- 
pending on the general relations of temperature and humidity, 
and on the form of mountains. On submitting these relations 
to the test of special analysis, as we may be permitted to do 
from the number of determinations that have recently been 
made,* we shall find that the controlling causes are the dif- 
ferences in the temperature of different seasons of the year ; 
the direction of the prevailing winds and their relations to the 
land and sea ; the degree of dryness or humidity in the upper 
strata of the air ; the absolute thickness of the accumulated 
masses of fallen snow ; the relation of the snow-line to the to- 
tal height of the mountain ; the relative position of the latter 
in the chain to which it belongs, and the steepness of its de- 
clivity ; the vicinity of other summits likewise perpetually 
covered with snow ; the expansion, position, and elevation of 
the plains from which the snow-mountain rises as an isolated 
peak or as a portion of a chain ; whether this plain be part 
of the sea-coast or of the interior of a continent ; whether it 
be covered with wood or waving grass ; and whether, finally, it 
consist of a dry and rocky soil, or of a wet and marshy bottom. 
The snow-line which, under the equator in South Ameri- 
ca, attains an elevation equal to that of the summit of Mont 
Blanc in the Alps, and descends, according to recent measure- 
ments, about 1023 feet lower toward the northern -tropic in 
the elevated plateaux of Mexico (in 19^ north latitude), rises, 
according to Pentland, in the southern tropical zone (14^ 30' 
to 18"^ south latitude), being more than 2665 feet higher in 
the maritime and western branch of the Cordilleras of Chili 
than under the equator near Quito on Chimborazo, Cotopaxi, 
and Antisana. Dr. Gillies even asserts that much further to 
the south, on the declivity of the volcano of Peuquenes (lati- 
tude 33*^), he found the snow-line at an elevation of between 
14,520 and 15,030 feet. The evaporation of the snow in the 
extremely dry air of the summer, and under a cloudless sky, 
is so powerful, that the volcano of Aconcagua, northeast of 
Valparaiso (latitude 32*^ 30'), which was found in the expe- 
dition of the Beagle to be more than 1400 feet higher than 
Chimborazo, was on one occasion seen free from snow.t In 

* See my table of the height of the line of perpetual snow, in both 
hemispheres, from 71° 15' north lat. to 53° 54' south lat., in my Asii 
Centrale, t. iii., p. 360. 

t Darwin, Journal of the Voyages of the Adventure and Beagle, p. 297 . 



THE SNOW-LINE. 381 

an almost equal northern latitude (from 30*^ 45' to 31*^), the 
snow-line on the southern declivity of the Himalaya lies at an 
elevation of 12,982 feet, which is about the same as the height 
which we might have assigned to it from a comparison with 
other mountain chains ; on the northern declivity, however, 
under the influence of the high lands of Thibet (whose mean 
elevation appears to be about 11,510 feet), the snow-line is 
situated at a height of 16,G30 feet. This phenomenon, Avhich 
has long been contested both, in Europe and in. India, and 
whose causes I have attempted to develop in various works, 
published since 1820,* possesses other grounds of interest than 

As the volcano of Aconcagua was not at that time in a state of eruption, 
we must not ascribe the remarkable phenomenon of the absence of 
snow to the internal heat of the mountain (to the escape of healed air 
through fissures), as is sometimes the case with Cotopaxi. Gillies, in 
the Journal of Natural Science, 1830, p. 316. 

* t>ee my Second Mernoire sur les Montagues de I'lnde, in the Annates 
de Chimic et de Physique, t. xiv., p. 5-55; and Asie Centrale, t. id., p. 
^81-327. While the most learned and experienced travelers in India, 
C(;lebr(ii)ke, Webb, and Hodgson, Victor Jacquemont, Forbes Royle, 
Carl von Hiigel, and V^igne, who have all personally examined the 
Himalaya range, are agreed regarding the greater elevation of the 
snuw-liue on the Thibetian side, the accuracy of this statement is called 
in question by John Gerard, by the geognosist MacClelland, the editor 
of the Calcutta Journal, and by Captain Thomas Hutton, assistant sur- 
veyor of the Agra Division. The appearance of my work on Central 
Asia gave rise to a redisciission of this question. A recent uumbei' (vol. 
iv,, January, 1844) of MacClelland and Griifith's Calcutta Journal of 
Natural History contains, however, a very remarkable and decisive no- 
tice of the determination of the snow-line in the Himalayas. Mr. Bat- 
ten, of the Bengal service, writes as follows from Camp Semulka, on the 
Cosillah Kiver, Kuma')n : "'In the .Tuly, 1843. No. 14 of your valuable 
Journal of Natural History, which I have only Litcly had tl^e o[!p.irtiiiii- 
ty of seeing, I read Captain Hutton's paper on the snow of the Hima- 
layas, and as I ditfered almost entirely from the conclusions s(j confi- 
dently drawn by that gentleman, T thought it right, fur the iniercst 
of scientitic truth, to prepare some kind of answer ; as, however, on a 
more attentive perusal, I find that you yourself appear implicitly to 
adopt Captain Hutton's views, and actually use these words, ' We have 
long been conscions of the error here so well pointed out by Captain 
Hutton, in common with every one who has visited the Himalayas,^ I ieel 
more inclined to address you, in the fiist instance, and to ask whether 
you will publish a short reply which I meditate; and whether your 
note to Captain Hutton's paper was written after your own full and 
careful examination of the subject, or merely on a general kind of ac- 
quiescence with the fact and opinions of your able contributor, who is 
so well known and esteemed as a collector of scientific data ? Now I 
am one who have visited the Himalaya on the w^estem side ; I have 
cros.sed the Bi);endo or Booriu Pass into the Buspa Valley, in Lower 
Kanawar, returning into the Revv'aien Mountains of Ghurwal by the 
Koopiu Pass; I have visited the source of the Jumna at Jumnootree i 



332 cosM ).s. 

those of a purely physical nature, since it exercises no incon- 
siderable desrree of influence on the mode of life of numerous 
tribes — the meteorological processes of the atmosphere being 
the controlling causes on which depend the agricultural ol* 
pastoral pursuits of the inhabitants of extensive tracts of con- 
tinents. 

As the quantity of moisture in the atmosphere increases 
with the temperature, this element, which is so important for 
the whole organic creation, must vary with the hours of the 
day, the seasons of the year, and the differences in latitude 
and elevation. Our knowledge of the hygrometric relations 
of the Earth's surface has been very materially augmented 
of late years by the general application of August's psychrom- 
eter, framed in accordance with the views of Dalton and 
Daniell, lor determining the relative quantity of vapor, or the 

and, moving eastward, the sources of the Kalee or Mundaknee branch 
of the Ganges at Kadarnath; of the Vishnoo Gunga, or Ahiknunda, at 
Buddrinath and Mana ; of the Pindur at the foot of the Great Peak 
Nundidevi; of the Dhoulee branch of the Ganges, beyond Neetee, cross- 
ing and recross^ng the pass of that name into Thibet; of the Goree or 
great branch of the Sardah, or Kalee, near Oonta Dhonra, beyond Me- 
lum. I have also, in my official capacity, made the settlement of the 
Bhote Mehals of this province. My residence of more than six years 
in the hills has thrown me constantly in the way of European and na- 
tive ti'avelcrs, nor have I neglected to acquire information from the re- 
corded labors of others. Yet, with all this experience, I am prepared 
to affirm that the perpetual snoic-line is at a higher elevation on the n(n'th- 
ern slope of ' the Himalaya' than on the southern slope. 

" The facts mentioned by Captain Hutton appear to me only to refer 
to the northern sides of all mountains in these regions, and not to affect, 
in any way, the reports of Captain Webb and others, on which Hum- 
boldt formed his theory. Indeed, how can any facts of one observer itt 
one place falsify the facts of another observer in another place ? I will- 
ingly allow that the north side of a hill retains the snow longer and 
deeper than the south side, and this observation applies equally to 
heights in Bhote ; but Humboldt's theory is on the question of the per- 
petual snow-line, and Captain Hulton's references to Simla and Mus- 
sooree, and other mountain sites, are out of place in this question, or 
else he fights against a shadow, or an objection of his own creation. 
In no part of his paper does he quote accurately the dictum which he 
wishes to oppose." 

If the mean altitude of the Thibetian highlands be 11,510 feet, they 
admit of comparison with the lovely and fruitful plateau of Caxarnarca 
in Peru. But at this estimate they would still be 1300 feet lower than 
the plateau of Bolivia at the Lake of Titicaca, and the causeway of the 
town of Potosi. Ladak, as appears from Vigne's measurement, by de- 
termining the boiling-point, is 9994 feet high. This is probably :ilso 
the altitude of H'Lassa (Yul-sung), a monastic city, which Chine.'^f' 
writers describe as the realm of pleasure, and which is snrroundfd by 
vineyards. Must not these lie in deep valleys? 



HYGROMETRY. • 333 

condition of moisture of the atmosphere, by means of the dif- 
ference of the deiv j^oint and of the temperature of the air. 
Temperature, atmospheric pressure, and the direction of the 
wind, are all intimately connected with the vivifying action 
of atmospheric moisture. This influence is not, however, so 
much a consequence of the quantity of moisture held in solu- 
tion in different zones, as of the nature and frequency of the 
precipitation which moistens the ground, whether in the form 
of dew, mist, rain, or snow. According to the exposition made 
by Dove of the law of rotation, and to the general views of 
this distinguished physicist,* it would appear that, in our 
northern zone, " the elastic force of the vapor is greatest with 
a southwest, and least with a northeast wind. On the west- 
ern side of the windrose this elasticity diminishes, while it in- 
creases on the eastern side ; on the former side, for instance, 
the cold, dense, and dry current of air repels the warmer, 
lighter current containing an abundance of aqueous vapor, 
while on the eastern side it is the former current which is 
repulsed by the latter. The southwest is the equatorial cur- 
rent, while the northeast is the sole prevailing polar current." 
The agreeable and fresh verdure which is observed in many 
trees in districts within the tropics, where, for five or seven 
months of the year, not a cloud is seen on the vault of heaven, 
and where no perceptible dew or rain falls, proves that the 
leaves are capable of extracting water from the atmosphere 
by a peculiar vital process of their own, which perhaps is not 
alone that of producing cold by radiation. The absence of 
rain in the arid plains of Cumana, Coro, and Ceara in North 
Brazil, forms a striking contrast to the quantity of rain which 
falls in some tropical regions, as, for instance, in the Havana, 
where it would appear, from the average of six years' observ- 
ation by Ramon de la Sagra, the mean annual quantity of 
rain is 109 inches, equal to four or five times that which falls 
at Paris or at Geneva. t On the declivity of the Cordilleras, 



it 



See Dove, Meteorologische Vergleichnng von Nordamerika vnd Eu- 
ropa, in Schumacher's Ja^r6McAy«r 1841, s. 311 ; and his Meteorologische 
Unfersuchungen, s. 140. 

t The mean annual quantity of rain that fell in Paris between 1805 
and 1822 was found by Arago to be 20 inches; in London, between 
1812 and 1827, it was determined by Howard at 25 inches; while at 
Geneva the mean of thirty-two years' observation was 30*5 inches. In 
Hindostan, near the coast, the quantity of rain is from 115 to 128 indies-; 
and in the island of Cuba, fully 142 inches fell in the year 1821. With 
regard to the distribution of the quantity of rain in Central Europe, at 
diSerent periods of the year, see the admirable researches of Ga3[)arin, 
Schouw, and Bravais, in the Bibliotheque Universelle, t. xxxviii., p. 54 



334 » COSMOS. 

the quantity of rain, as well as the temperature, diminishes 
with the increase in the elevation.* My South American 
fellow-traveler, Caldas, found that, at Santa Fe de Bogota, 
at an elevation of almost 8700 feet, it did not exceed 37 
inches, heing consequently little more than on some parts of 
the western shore of Europe. Boussingault occasionally ob- 
served at Quito that Saussure's hygrometer receded to 26° 
with a temperature of from 530-6 to 55°-4. Gay-Lussac 
saw the same hygrometer standing at 25° -3 in his great aero- 
static ascent in a stratum of air 7034 feet high, and wath a 
temperature of 39°-2. The greatest dryness that has yet 
been observed on the surface of the globe in low lands is 
probably that which Gustav Pwose, Ehrenberg, and myself 
found in Northern Asia, between the valleys of the Irtisch 
and the Oby. In the Steppe of Platowskaja, after southwest 
winds had bloAvn for a long time from the interior of the Con- 
tinent, with a temperature of 74°-7, w^e found the dew point 
at 24°. The air contained only yVo^^i^ ^f aqueous vapor. f 
The accurate observers Kamtz, Bravais, and Martins have 
raised doubts during the last few years regarding the greater 
dryness of the mountain air, which appeared to be proved by 
the hygrometric measurements made by Saussure and my- 
self in the higher regions of the Alps and the Cordilleras. 
The strata of air at Zurich and on the Faulhorn, which can 
not be considered as an elevated mountain when compared 
with non-European elevations, furnished the data employed 
in the comparisons made by these observers. $ In the tropical 
region of the Paramos (near the region where snow begins to 
fall, at an elevation of between 12,000 and 14,000 feet), some 
species of large flowering myrtle-leaved alpine shrubs are al- 
most constantly bathed in moisture ; but this fact does not 
actually prove the existence of any great and absolute quan- 
tity of aqueous vapor at such an elevation, merely afibrding 

and 264; Tableau du Climat de V Italic, p. 76; and Marlins's notes lo 
his excellent French translation of Kamtz's VorlesJtngeri uber MeUurol- 
ogie, p. 142. 

* According to Boussinganlt {Economic Rurale, t. ii., p. 603), fht- 
mean quantity of rain that fell at Marmato (latitude .5° 27', altilu.ii; 
4675 feet, and mean temperature 69°) in the years 1833 and 1834 \v;is 
64 inches, while at Santa Fe de Bogota (latitude 4° 36', altitude 8083 
feet, and mean temperature 58°) it only amounted to 39^ inches. 

t For the particulars of this observation, see my Asic Centrale, t. iii. 
p. 85-89 and 567 ; and regarding the amount of vapor in the atnio> 
phere in the lowlands of tropical South America, consult my R6lal 
Hist., t. i., p. 242-248; t. ii., p. 45, 164. 

\ Kamtz, Vo.rlesungen uber Mcicorologie, s. 117. 



ATMOSPHERIC ELECTRICITY. 335 

ail evidence of the frequency of aqueous precipitation, in like 
manner as do the frequent mists with which the lovely pla- 
teau of Bogota is covered. Mists arise and disappear several 
limes in the course of an hour in such elevations as these, and 
with a cahii state of the atmosphere. These rapid alterna 
tions characterize the Paramos and the elevated plains of the 
chain of the Andes. 

The electricity of the atmosphere, whether considered in 
the lower or in the upper strata of the clouds, in its silent 
prohlematical diurnal course, or in the explosion of the light- 
ning and thunder of the tempest, appears to stand in a mani- 
fold relation to all phenomena of the distribution of heat, of 
the pressure of the atmosphere and its disturbances, of hydro- 
meteoric exhibitions, and probably, also, of the magnetism of 
the external crust of the earth. It exercises a powerful in- 
fluence on the whole animal and vegetable world ; not mere- 
ly by meteorological processes, as precipitations of aqueous va- 
por, and of the acids and ammoniacal compounds to which it 
gives rise, but also directly as an electric Ibrce acting on the 
nerves, and promoting the circulation of the organic juices. 
This is not a place in which to renew the discussion that has 
been started regarding the actual source of atmospheric elec- 
tricity when the sky is clear, a phenomenon that has altern 
ately been ascribed to the evaporation of impure fluids im- 
pregnated with earths and salts,* to the growth of plants,! or 
to some other chemical decompositions on the surface of the 
earth, to the unequal distribution of heat in the strata of the 
air,| and, finally, according to Peltier's intelligent researches,^ 
to the agency of a constant charge of negative electricity in 
the terrestrial globe. Limiting itself to results yielded by 
electrometric observations, such, for instance, as are furnished 
by the ingenious electro-magnetic apparatus first proposed by 
CoJladon, the physical description of the universe should 
merely notice the incontestable increase of intensity in the 
general positive electricity of the atmosphere, II accompanying 
an increase of altitude and the absence of trees, its daily va- 
riations (which, according to Clark's experiments at Dublin, 

* Regarding the conditions of electricity from evaporation at higb 
temperatures, see Peltier, in the Annales de Chimie, t. Ixxv., p. 3-30 

t Pouillet, in the Annales de Chimie, t. xxxv., p. 405. 

t De la Rive, in his admirable Essai Historique snr V ElcctriciU, p. 
140. 

^ Peltier, in the Compies Rendus de V Acad, des Sciences, t. xii., p. 
307 ; Becquerel, Traile de VElec(ricit6 et du Magnetismc, t. iv., p. 10?" 

1] Duprez, Sur V Electriciti de VAir (BruxcUes, 181 i), p. 5(5-61 



336 COSMOS. 

take place at more complicated periods than those found by 
Saussure and myself), and its variations in the different 
seasons of the year, at different distances from the equator, 
and in the difierent relations of continental or oceanic sur- 
face. 

The electric equilibrium is less frequently disturbed where 
the aerial ocean rests on a liquid base than where it impends 
over the land ; and it is very striking to observe how, in ex- 
tensive seas, small insular groups affect the condition of the 
atmosphere, and occasion the formation of storms. In fogs, 
and in the commencement of falls of snov/, I have seen, in a 
long series of observations, the previously permanent positive 
electricity rapidly pass into the negative condition, both on 
the plains of the colder zones, and in the Paramos of the Cor- 
dilleras, at elevations varying from 11,000 to 15,000 feet. 
The alternate transition was precisely similar to that indica- 
ted by the electrometer shortly before and during a storm.* 
When the vesicles of vapor have become condensed into clouds, 
having definite outlines, the electric tension of the external 
surface will be increased m proportion to the amount of elec- 
tricity which passes over to it from the separate vesicles of 
vapor.f Slate-gray clouds are charged, according to Peltier's 
experiments at Paris, with negative, and white, red, and or- 
ange-colored clouds with positive electricity. Thunder clouds 
not only envelop the highest summits of the chain of the An- 
des (I have myself seen the electric effect of lightning on one 
of the rocky pinnacles which project upward of 15,000 feet 
above the crater of" the volcano of Toluca), but they have also 
been observed at a vertical height of 26,650 feet over the low 

* Humboldt, Relation Historique, t. iii., p. 318. I here only refer 
to those of my experiments in which the three-foot metallic conductor 
of Saussure's electrometer was neither moved upward nor downward, 
nor, according to Volta's proposal, armed with burning sponge. Those 
of my readers who are well acquainted with the qufcaliones vexatce of 
atmospheric electricity will understand the grounds for this limitation. 
Respecting the formation of storms in the tropics, see my Ril. Hist., t. 
ii., p. 45 and 202-209. 

t Gay-Lussac, in the Annales de Chimie et de Physique, t. viii., p. 167. 
In consequence of the discordant views of Lame, Becquerel, and Pel- 
tier, it is difficult to come to a conclusion regarding the cause of the 
specific distribution of electricity in clouds, some of which have a pos- 
itive, and others a negative tension. The negative electricity of the 
air, which near high water-falls is caused by a disintegration of the 
drops of water — a fqct originally noticed by Tralles, and confirmed by 
myself in various latitudes — is very remarkable, and is suflSciently in- 
tense to produce an appreciable effect on a delicate electrometer at a 
diatance of 300 or 400 feet. 



ATMOSPHERIC ELECTRICITY. 337 

lands in the temperate zone.* Sometimes, however, the 
stratum of cloud from which the thunder proceeds sinks to a 
distance of 5000, or, indeed, only 3000 feet above the plain. 

According to Arago's investigations — the most comprehen- 
sive that we possess on this difficult branch of meteorology — 
the evolution of light (lightning) is of three kinds — zigzag, 
and sharply defined at the edges ; in sheets of light, illumin- 
ating a whole cloud, which seems to open and reveal the light 
within it ; and in the form of fire-balls. t The duration of the 
two first kinds scarcely continues the thousandth part of a 
second ; but the globular lightning moves much more slowly 
remaining visible for several seconds. Occasionally (as is 
proved by the recent observations, which have confirmed the 
description given by Nicholson and Beccaria of this phenom- 
enon), isolated clouds, standing high above the horizon, con- 
tinue uninterruptedly for some time to emit a luminous ra- 
diance from their interior and from their margins, although 
there is no thmider to be heard, and no indication of a storm ; 
in some cases even hail-stones, drops of rain, and flakes of snow 
have been seen to fall in a luminous condition, when the phe- 
nomenon was not preceded by thunder. In the geographical 
distribution of storms, the Peruvian coast, which is not visited 
by thunder or lightning, presents the most striking contrast to 
the rest of the tropical zone, in which, at certain seasons of 
the year, thunder-storms occur almost daily, about four or five 
hours after the sun has reached the meridian. According to 
the abundant evidence collected by Arago$ from the testimony 
of navigators (Scoresby, Parry, Ross, and Frankhn), there can 
be no doubt that, in general, electric explosions are extremely 
rare in high northern regions (between 70^^ and 75° latitude). 

The meteorological portion of the descriptive history of na- 
ture which we are now concluding shows that the processes 
of the absorption of light, the liberation of heat, and the va- 
riations in the elastic and electric tension, and in the hygro- 
metric condition of the vast aerial ocean, are all so intimate- 
ly connected together, that each individual meteorological 
process is modified by the action of all the others. The com- 

* Arago, in the Annuaire dn Bureau des Longitudes pour 1838, p. 246. 
t Arago, op. cit., p. 249-266. (See, also, p. 268-279.) 
X Arago, op, cit., p. 388-391. The learned academician Von Baer, 
who has done so much for the meteorology of Northern Asia, has not 
taken into consideration the extreme rarity of storms in Iceland and 
Greenland ; he has only remarked {Bulletin de V Academie de St. Piters- 
bourg, 1839, Mai) that in Nova Zembla tmd Spitzbergen it is sometimes 
heard to thunder. 

Vol. I.— P 



338 COSMOS. 

plicated nature of these disturbing causes (wliich involuntarily 
remind us of those which the near and especially the smallest 
cosmical bodies, the satellites, comets, and shooting stars, are 
Bubjected to in their course) increases the difficulty of giving a 
full explanation of these involved meteorological phenomena, 
and likewise limits, or wholly precludes, the possibility of that 
predetermination of atmospheric changes which would be so 
important for horticulture, agriculture, and navigation, no less 
than for the comfort and enjoyment of life. Those who place 
the value of meteorology in this problematic species of predic- 
tion rather than in the knowledge of the phenomena them- 
selves, are firmly convinced that this branch of science, on ac- 
count of which so many expeditions to distant mountainous 
regions have been undertaken, has not made any very consid- 
erable progress for centuries past. The confidence which they 
refuse to the physicist they yield to changes of the moon, and 
to certain days marked in the calendar by the superstition of 
a by-gone age. 

" Great local deviations from the distribution of the mean 
temperature are of rare occurrence, the variations being in 
general uniformly distributed over extensive tracts of land. 
The deviation, after attaining its maximum at a certain point, 
gradually decreases to its limits ; when these are passed, how- 
ever, decided deviations are observed in the opjJodte direction. 
Similar relations of weather extend more frequently from south 
to north than from west to east. At the close of the year 1829 
(when I had just completed my Siberian journey), the maxi- 
mum of cold was at Berlin, while North America enjoyed an 
mmsually high temperature. It is an entirely arbitrary as- 
sumption to believe that a hot summer succeeds a severe win- 
ter, and that a cool summer is preceded by a mild winter." 
Opposite relations of weather in contiguous countries, or in 
two corn-growing continents, give rise to a beneficent equali- 
zation in the prices of the products of the vine, and of agricul- 
tural and horticultural cultivation. It has been justly re- 
marked, that it is the barometer alone which indicates to us 
the changes that occur in the pressure of the air throughout 
all the aerial strata from the place of observation to the ex- 
tremest confines of the atmosphere, while* the thermometer 
and psychrometer only acquaint us with all the variations oc- 
curring in the local heat and moisture of the lower strata of 

* Kamtz, ill Schumacher's Jahrhuch fur 1838, s. 285. Regarding 
the opposite distribution of lieat in the east and the west of Europe ;iiiil 
North America, see Dove. Repertorium dcr Physik, bd. iii.. s. 392-305. 



ORGANIC LIFE, 339 

air in contact with the ground. The simultaneous thermic 
and hygrometric modifications of the upper regions of the air 
can only be learned (when direct observations on mountain 
stations or aerostatic ascents are impracticable) from hypo- 
thetical combinations, by making the barometer serve both as 
a thermometer and an hygrometer. Important changes of 
weather are not owing to merely local causes, situated at the 
place of observation, but are the consequence of a disturbance 
in the equilibrium of the aerial currents at a great distance 
from the surface of the Earth, in the higher strata of the at- 
mosphere, bringing cold or warm, dry or moist air, rendering 
the sky cloudy or serene, and converting the accumulated 
masses of clouds into light feathery cirri. As, therefore, the 
inaccessibility of the phenomenon is added to the manifold 
nature and complication of the disturbances, it has always 
appeared to me that meteorology must first seek its founda- 
tion and progress in the torrid zone, where the variations of 
the atmospheric pressure, the course of hydro-meteors, and 
the phenomena of electric explosion, are all of periodic occur- 
rence. 

As we have now passed in review the whole sphere of in- 
organic terrestrial life, and have briefly considered our planet 
with reference to its form, its internal heat, its electro-mag- 
netic tension, its phenomena of polar light, the volcanic reac- 
tion of its interior on its variously composed solid crust, and, 
lastly, the phenomena of its two-fold envelopes — the aerial and 
liquid ocean — we might, in accordance with the older method 
of treating physical geography, consider that we had com- 
pleted our descriptive history of the globe. But the nobler 
aim I have proposed to myself, of raising the contemplation 
of nature to a more elevated point of view, would be defeated, 
and this delineation of nature would appear to lose its most 
attractive charm, if it did not also include the sphere of or- 
ganic life in the many stages of its typical development. The 
idea of vitality is so intimately associated with the idea of the 
existence of the active, ever-blending natural forces which an- 
imate the terrestrial sphere, that the creation of plants and 
animals is ascribed in the most ancient mythical representa- 
tions of many nations to these forces, while the condition of 
the surface of our planet, before it was animated by vital 
forms, is regarded as coeval with the epoch of a chaotic 
conflict of the struggling elements. But the empirical do- 
main of objective contemplation, and the delineation of our 
planet in its present condition, do not include a consideration 



340 COSMOS. 

of the mysterious and insoluble prolDlenis of origin and exist- 
ence. 

A cosmical history of the universe, resting upon facts as its 
basis, has, from the nature and limitations of its sjDhere, neces- 
sarily no connection with the obscure domain embraced by a 
history of organisms* if we understand the word history in 
its broadest sense. It must, however, be remembered, that 
the inorganic crust of the Earth contains within it the same 
elements that enter into the structure of animal and vegeta- 
ble organs. A physical cosmography would therefore be in 

* The history of plants, which Eudlicher and Unger have described 
in a most masterly manner {Grundzuge der Botanik, 1843, s. 449-468), 
I myself separated from the geography of plants half a century ago 
In the aphorisms appended to my Subterranean Flora, the following 
passage occurs : " Geognosia naturam animantem et inanimam vel, ut 
vocabulo minus apto, ex antiquitate saltem hand petito, utar, corpora 
orgauica aeque ac inorganica considerat. Sunt enim tria quibus absol 
vitur capita : Geographia oryctologica quam simpliciter Geognosiam vel 
Geologiam dicunt, virque acutissimus Wemerus egregie digessit ; Geo- 
graphia zoologica, cujus doctrinse fundamenta Zimmermannus et Tre- 
virauus jecerunt; et Geographia plantarum quam sequales nostri diu in- 
tactam reliquerant. Geographia plantarum vincula et cognationem 
tradit, quibus omnia vegetabilia inter se connexa sint, ten-ae tractus 
quos teueant, in aerem atmosphasricum qui3e sit eorum vis ostendit, saxa 
atque rupes quibus potissimum algarum primordiis radicibusque destru- 
antur docet, et quo pacto in telluris superficie humus nascatur, com- 
memorat. Est itaque quod dilFerat inter Geognosiam et Physiographiam, 
historia naturalis perperam imncupatam quum Zoognosia, Phytognosia, 
et Oryctognosia, quse quidem omnes in naturae investigatione versantur, 
non nisi singulorum animalium, plantarum, rerum metallicanim vel 
(venia sit verbo) fossilium formas, anatomen, vires scrutantur. Historia 
Telluris, Geognosiae magis quam Physiographiae affinis, nemini adhuc 
tentata, plantarum animaliumque genera orbem inhabitantia primaevum, 
migrationes eorum compluriumque interitum, ortum quem montes, 
valles, saxorura strata et venae metalliferoe ducunt, aerem, mutatis tem- 
porum vicibus, modo purum, modo vitiatum, teiTas superficiem humo 
plantisque paulatim obtectam, fluminum inundantium impetu denuo 
nudatam, iteruraque siccatam et gramine vestitam commemorat. Igi- 
tur Historia zoologica, Historia plantarum et Historia oryctologica, quaa 
non nisi pristinum orbis terrae statum indicant, a Geognosia probe dis- 
tinguendai." — Humboldt, Flora Friburgensis Subterranea, cui accedunt 
Aphorismi ex Physiologia Chemica Plantarum, 1793, p. ix.-x. Respect- 
ing the " spontaneous motion," which is referred to in a subsequent 
part of the text, see the remarkable passage in Aristotle, De Codo, ii., 
2, p. 284, Bekker, where the distinction between animate and inanimate 
bodies is made to depend on the internal or external position of the 
seat of the determining motion. " No movement," says the Stagirite, 
" proceeds fi'om the vegetable spirit, because plants are buried in a 
Btill sleep, from which nothing can arouse them" (Aristotle, De General. 
Animal., v. i., p. 778, Bekker); and again, "because plants have no 
desires which incite them to spontaneous motion." (Arist., De Sovino 
et Vigil., cap. i., p. 455, Bekker.) 



MOTION IN PLANTS. 341 

complete if it were to omit a consideration of these forces, and 
of the substances which enter into sohd and fluid combina- 
tions in organic tissues, under conditions which, from our igno- 
rance of their actual nature, we designate by the vague terra 
of vital forces, and group into various systems, in accordance 
with more or less perfectly conceived analogies. The nat- 
ural tendency of the human mind involuntarily prompts us 
to follow the physical phenomena of the Earth, through all 
their varied series, until we reach the final stage of the mor- 
phological evolution of vegetable forms, and the self-determin- 
ing powers of motion in animal organisms. And it is by these 
links that the geography of wganic beings — of plants and 
animals — is connected with the delineation of the inorganic 
phenomena of our terrestrial globe. 

Without entering on the difficult question of sjiontaneous 
motion, or, in other words, on the difference between vegeta- 
ble and animal life, we would remark, that if nature had en- 
dowed us with microscopic powers of vision, and the integu- 
ments of plants had been rendered perfectly transparent to 
our eyes, the vegetable world would present a very different 
aspect from the apparent immobility and repose in which it 
is now manifested to our senses. The interior portion of the 
cellular structure of their organs is incessantly animated by 
the most varied currents, either rotating, ascending and de- 
scending, ramifying, and ever changing their direction, as 
manifested in the motion of the granular mucus of marine 
plants (Naiades, Characea3, HydrocharidsB), and in the hairs of 
phanerogamic land plants ; in the molecular motion first dis- 
covered by the illustrious botanist Robert Brown, and which 
may be traced in the ultimate portions of every molecule of 
matter, even when separated from the organ ; in the gyratorv 
currents of the globules of cambium {cyclosis) circulating in 
their peculiar vessels ; and, finally, in the singularly articula- 
ted self-unrolling filamentous vessels in the antheridia of the 
chara, and in the reproductive organs of liverworts and algae, 
in the structural conditions of which Meyen, unhappily too 
early lost to science, believed that he recognized an analogy 
with the spermatozoa of the animal kingdom.* If to these 

* [" la certain parts, probably, of all plants, are found peculiar spiral 
filaments, having a striking resemblance to the spermatozoa of animals. 
They have been long known in the organs called the antheridia of 
musses, Hepaticn", and Characea?, and have more recently been dis- 
covered in peculiar cells on the germinal frond of ferns, and on the 
very young leaves of the buds of^Phanerogamia. They are found in 
peculiar cells, and when these are placed in water they are torn by the 



342 COSMOS. 

manifold currents and gyratory movements we add the phe- 
nomena of endosmosis, nutrition, and growth, we shall have 
some idea of those forces which are ever active amid the ap- 
parent repose of vegetable life. 

Since I attempted in a former work, Ansichten der Natur 
(Views of Nature), to delineate the universal diffusion of life 
over the whole surface of the Earth, in the distribution of 
organic forms, both with respect to elevation and depth, our 
knowledge of this branch of science has been most remarkably 
increased by Ehrenberg's brilliant discovery " on microscopic 
life in the ocean, and in the ice of the polar regions" — a dis- 
covery based, not on deductive conclusions, but on direct ob- 
servation. The sphere of vitality, we might almost say, the 
horizon of life, has been expanded before our eyes. " Not 
only in the polar regions is there an uninterrupted develop- 
ment of active microscopic life, where larger animals can no 
longer exist, but we find that the microscopic animals collect- 
ed in the Antarctic expedition of Captain James Ross exhibit 
a remarkable abundance of unknown and often most beautiful 
forms. Even in the residuum obtained from the melted ice, 
swimming about in round fragments in the latitude of 70^ 10', 
there were found upward of fifty species of silicious-shelled 
Polygastria and CoscinodiscsB with their green ovaries, and 
therefore living and able to resist the extreme severity of the 
cold. In the Gulf of Erebus, sixty-eight silicious-shelled Poly- 
gastria and Phytolitharia, and only one calcareous-shelled Poly- 
thalamia, were brought up by lead sunk to a depth of from 
1242 to 1620 feet." 

The greater number of the oceanic microscopic forms hith- 
* rto discovered have been silicious-shelled, although the anal- 
ysis of sea water does not yield silica as the main constituent, 
and it can only be imagined to exist in it in a state of suspen- 
sion. It is not only at particular points in inland seas, or in 
the vicinity of the land, that the ocean is densely inhabited 
by living atoms, invisible to the naked eye, but samples of 

filament, which commences an active spiral motion. The signification 
of these organs is at present quite unknown ; they appear, from the 
researches of Nageli, to resemble the cell mucilage, or proto-plasma, 
in composition, and are developed from it. Schleiden regards them as 
mei'e mucilaginous deposits, similar to those connected with the circu- 
lation in cells, and he contends that the movement of these bodies in 
water is analogous to the molecular motion of small particles of organic 
and inorganic substances, and depends on mechanical causes." — Outlines 
of Structural and Physiological Botany, by A. Henfrey, F.L.S., &c., 
1846, p. 23.]— Tr 



UNIVERSALITY Ol' ANIMAL LIFE. 'MH 

water taken up by Schayer on his return from Van Diemen's 
Laud (south of the Cape of Good Hope, in 57° latitude, and 
under the trojoics in the Atlantic) show that the ocean in its 
ordinary condition, without any apparent discoloration, con- 
tains numerous microscopic moving organisms, which bear no 
resemblance to the swimming fragmentary silicious filaments 
of the genus Chaetoceros, similar to the Oscillatoria3 so common 
in our fresh waters. Some few Polygastria, which have been 
found mixed with sand and excrements of penguins in Cock- 
burn Island, appear to be spread over the whole earth, while 
others seem to be peculiar to the polar regions. "^ 

We thus find from the most recent observations that ani- 
mal life predominates amid the eternal night of the depths of 
ocean, while vegetable life, which is so dependent on the pe- 
riodic action of the solar rays, is most prevalent on continents. 
The mass of vegetation on the Earth very far exceeds that 
of animal organisms ; for what is the volume of all the large 
living Cetacea and Pachydermata when compared wdth the 
thickly-crowded colossal trunks of trees, of from eight to twelve 
feet in diameter, which fill the vast forests covering the trop- 
ical region of South America, between the Orinoco, the Ama- 
zon, and the Rio da Madeira ? And although the character 
of different portions of the earth depends on the combination 
of external phenomena, as the outlines of mountains — the 
physiognomy of plants and animals — the azure of the sky — 
the forms of the clouds — and the transparency of the atmos- 
phere — it must still be admitted that the vegetable mantle 
with which the earth is decked constitutes the main feature 
of the picture. Animal forms are inferior in mass, and their 
powers of motion often withdraw them from our sight. The 

* See Ehrenberg's treatise Ueber das kleinste Leben im Ocean, I'ead 
before the Academy of Science at Berlin on the 9th of May, 1844. 

[Dr. J. Hooker found Diatomace;c in countless numbers between the 
parallels of 60° and 80° south, where they gave a color to the sea, and 
also to the icebergs floating in it. The death of these bodies in the 
South Arctic Ocean is producing a submarine deposit, consisting en- 
tirely of the silicious particles of which the skeletons of these vegeta- 
bles are composed. This deposit exists on the shores of Victoria Land 
and at the base of the volcanic mountain Erebus. Dr. Hooker account- 
ed for the fact that the skeletons of Diatoraaceae had been found in the 
lava of volcanic mountains, by referring to these deposits at Mount 
Erebus, which lie in such a position as to render it quite possible that 
the skeletons of these vegetables should pass into the lower fissures of 
the mountain, and then passing into the stream of lava, be thrown out, 
unacted upon by the heat to which they have been exposed. See Dr. 
Hooker's Pajier, read before the British Association at Oxford, July, 
1847.]— Tr. 



344 cosMoa. 

vegetable kingdom, on the contrary, acts upon our imagination 
by its continued presence and by the magnitude of its forms ; 
for the size of a tree indicates its age, and here alone ag^e is 
associated with the expression of a constantly renewed vigor.* 
In the animal kingdom (and this knowledge is also the result 
of Ehrenberg's discoveries), the forms which we term micro- 
scopic occupy the largest space, in consequence of their rapid 
propagation.! The minutest of the Infusoria, the Monadidse, 
have a diameter which does not exceed 3 oVo^^ ^f a line, and 
yet these silicious-shelled organisms form in humid districts 
subterranean strata of many fathoms in depth. 

The strong and beneficial influence exercised on the feelings 
of mankind by the consideration of the diffusion of life through- 
out the realms of nature is common to every zone, but the im- 
pression thus produced is most powerful in the equatorial re- 
gions, in the land of palms, bamboos, and arborescent ferns, 
where the ground rises from the shore of seas rich in mollusca 
and corals to the limits of perpetual snov/. The local distri- 
bution of plants embraces almost all heights and all depths. 
Organic forms not only descend into the interior of the earth, 
where the industry of the miner has laid open extensive ex- 
cavations and sprung deep shafts, but I have also found snow- 
white stalactitic columns encircled by the delicate web of an 
Usnea, in caves where meteoric water could alone penetrate 
through fissures. Podurellae penetrate into the icy crevices of^ 
the glaciers on Mount Rosa, the Grindelwald, and the Upper 
Aar ; the Chionsea araneoides described by Dalman, and the 
microscopic Discerea nivalis (formerly known as Protococ- 
cus), exist in the polar snow as well as in that of our high 
mountains. The redness assumed by the snow after lying on 
the ground for some time was known to Aristotle, and was 
probably observed by him on the mountains of Macedonia.! 

* Humboldt, Ansichten der Nairn- (2te Ausgabe, 1826), bd. ii., s. 21. 

t On multiplication by spontaneous division of the mother-corpuscle 
and iutercalation of new substance, see Ehrenberg, Von den jetzt leben- 
den Thierarten der Kreidebildung, in the Abkandl. der Berliner Akad. 
der Wiss., 1839, s. 94. The most powerful productive faculty in na- 
ture is that manifested in the Vorticellse. Estimations of the greatest 
possible development of masses will be found in Ehrenberg's great 
work. Die Infus^ionsthierchen als vollkommne Organismen, 1838, s. xiii., 
xix., and 244. " The Milky Way of these organisms comprises the 
genera Monas, Vibrio, Bacterium, and Bodo." The universality of life 
is so profusely distributed throughout the whole of nature, that the small- 
er Infusoria live as parasites on the larger, and are themselves iii&abit- 
ed by others, s. 194, 211, and 512. 

t Aristot.. Hist. Animal., v. xix., p. 552, Bekk. 



UNIVERSALITY OF ANIMAL LIFE. 345 

While, on the loftiest summits of the Alps, only Lecidese, 
Parmeliae, and Umbilicariai cast their colored but scanty 
covering over the rocks, exposed by the melted snow, beauti- 
ful phanerogamic plants, as the Culcitiura rufescens, Sida 
pinchinchensis, and Saxifraga Boussingaulti, are still found 
to flourish in the tropical region of the chain of the Andes, at 
an elevation of more than 15,000 feet. Thermal springs con- 
tain small insects (Hydroporus thermalis), Gallionellae, Oscilla- 
toria, and Confervse, while their waters bathe the root-fibers of 
phanerogamic plants. As air and water are animated at dif- 
ferent temperatures by the presence of vital organisms, so like- 
wise is the interior of the different portions of animal bodies. 
Animalcules have been found in the blood of the frog and the 
salmon ; according to Nordmann, the fluids in the eyes of fishes 
are often filled with a worm that lives by suction (Diplosto- 
mum), while in the gills of the bleak the same observer has 
discovered a remarkable double animalcule (Diplozoon para- 
doxum), having a cross-shaped form with two heads and two 
caudal extremities. 

Although the existence of meteoric Infusoria is more than 
doubtful, it can not be denied that, in the same manner as the 
pollen of the flowers of the pine is observed every year to fall 
from the atmosphere, minute infusorial animalcules may like- 
wise be retained for a time in the strata of the air, after hav- 
ing been passively borne up by currents of aqueous vapor.* 
This circumstance merits serious attention in reconsidering 
the old discussion respecting sjwntaneous generation,! and the 

* Ehrenberg, op. cit., s. xiv., p. 122 and 493. This rapid multiplica- 
tion of microscopic organisms is, in the case of some (as, for instance, 
ia wheat-eels, wheel-animals, and water-bears or tardigrade animal- 
cules), accompanied by a remarkable tenacity of life. They have been 
seen to come to life from a state of apparent death after being dried 
for twenty-eight days in a vacuum with chloride of lime and sulphuric 
acid, and after being exposed to a heat of 248°. See the beautiful ex- 
periments of Doyere, in M6jn. sur les Tardigrades et sur leur propriety 
de revenir a la vie, 1842, p. 119, 129, 131, 133. Compare, also, Ehren 
berg, s. 492-496, on the revival of animalcules that had been dried 
during a space of many years. 

t On the supposed ''primitive transformation" of organized or uuor 
ganized matter into plants and animals, see Ehrenberg, in Poggen- 
dorf's Annalen der Physik. bd. xxiv., s. 1—48, and also his Infusions- 
thierchen, s. 121, 525, and Joh. Miiller, Physiologic des Menschen (4te 
Aufl., 1844), bd. i., s. 8-17. It appears to me worthy of notice that one 
of the early fathers of the Church, St. Augiistino. in treating of the 
question how islands may have been covered with new animals and 
plants after the flood, shows himself in no way disinclined to adopt the 
view of the so-called " spontaneous generation" (generatio cpquivoca, 

P 2 



346 COSMOS. 

more so, as Ehrenberg, as I have already remarked, has dis- 
covered that the nebulous dust or sand which mariners often 
encounter in the vicinity of the Cape Verd Islands, and even 
at a distance of 380 geographical miles from the African shore, 
contains the remains of eighteen species of sihcious-shelled pol- 
ygastric animalcules. 

Vital organisms, whose relations in space are compris^ed un- 
der the head of the geography of plants and animals, may be 
considered either according to the difference and relative num- 
bers of the types (their arrangement into genera and species), 
or according to the number of individuals of each species on a 
given area. In the mode of life of plants as in that of ani- 
mals, an important difference is noticed ; they either exist in 
an isolated state, or live in a social condition. Those species 
of plants which I have termed social* uniformly cover vast 
extents of land. Among these we may reckon many of the 
marine Algae — Cladoniae and mosses, which extend over the 
desert steppes of Northern Asia — grasses, and cacti growing 

spontanea aut primaria). " If," says he, " animals liave not been 
brought to remote islands by angels, or perhaps by inhabitants of con 
tinents addicted to the chase, they must have been spontaneously pro- 
duced upon the earth ; although here the question certainly arises, to 
what purpose, then, were animals of all kinds assembled in the ark?" 
" Si e terra exortas sunt (bestise) secundum originem primam, quando 
dixit Deus: Producat terra animam vivam ! multo clarius apparet, non 
tam reparandorum animalium causa, quam figurandarum variarum gen- 
tium (?) propter ecclesiee sacramentum in area fuisse omnia genera, si in 
insulis quo trausire non possent, multa animalia terra pi'oduxit." Augus- 
tinus, De Civitate Dei, lib. xvi., cap. 7 ; Opera, ed. Monach. Ordinis S. 
Benedicti, t. vii., Venet., 1732, p. 422. Two centuries before the time of 
the Bishop of Hippo, we find, by extracts from Trogus Pompeius, that 
the generatio primaria was brought foi'ward in connection with the 
earliest drying up of the ancient world, and of the high table-land oi 
Asia, precisely in the same manner as the terraces of Paradise, in the 
theory of the great Linna-us, and in the visionary hypotheses entertain- 
ed in the eighteenth century regarding the fabled Atlantis: "Quod si 
omnes quondam terrae submersae profundo fuerunt, profecto editissi- 
mam quamque partem decurrentibus aquis primum detectam ; humil- 
limo autem solo eandem aquam diutissime immoratam, et quanto prior 
quteque pars terrarum siccata sit, tanto prius animalia generare coepisse. 
Porro Scythiam adeo editiorem omnibus terris esse ut cuncta flumina 
ibi nata in Maeotium, turn delude in Ponticum et iEgyptium mare de- 
currant." — Justinus, lib. ii., cap. 1. The erroneous supposition that the 
land of Scythia is an elevated table-land, is so ancient that we meet 
with it most clearly expressed in Hippocrates, De yEre et Aquis, cap. 
6, $ 96, Coray. •' Scythia," says he, " consists of high and naked 
plains, which, without being crowned with mountains, ascend higher 
and higher toward the north." 

* Humboldt, Aphorismi ex Physiologia Chemica Plantarum, in the 
Flora Fribergensis Suhterranea, 1793, {). 178. 



GEOGRAPHY OF PLANTS. 347 

together like the pipes of au organ — Avicenniae and mangroves 
in the tropics — and forests of Coniferse and of birches in the 
plains of the Baltic and in Siberia. This mode of geographical 
distribution determines, together with the individual form of 
the vegetable world, the size and type of leaves and flowers, 
in fact, the principal physiognomy of the district ;* its charac- 
ter being but little, if at all, influenced by the ever-moving 
forms of animal life, which, by their beauty and diversity, so 
powerfully affect the feeHngs of man, whether by exciting the 
sensations of admiration or horror. Agricultural nations in- 
crease artificially the predominance of social plants, and thus 
augment, in many parts of the temperate and northern zones, 
the natural aspect of uniformity ; and while their labors tend 
to the extirpation of some wild plants, they likewise lead to 
the cultivation of others, which follow the colonist in his most 
distant migration. The luxuriant zone of the tropics oflers 
the strongest resistance to these changes in the natural distri- 
bution of vegetable forms. 

Observers who in short periods of time have passed over 
vast tracts of land, and ascended lofty mountains, in which 
climates were ranged, as it were, in strata one above another, 
must have been early impressed by the regularity with which 
vegetable forms are distributed. The results yielded by their 
observations furnished the rough materials for a science, to 
which no name had as yet been given. The same zones or 
regions of vegetation which, in the sixteenth century, Cardinal 
Bembo, when a youth,! described on the declivity of yEtna, 
were observed on Mount Ararat by Tournefort. He ingen- 
iously compared the Alpine flora with the flora of plains situ- 
ated in different latitudes, and was the first to observe the in- 
fluence exercised in mountainous regions, on the distribution 
of plants by the elevation of the ground above the level of 
the sea, and by the distance from the poles in flat countries. 
Menzel, in an inedited work on the flora of Japan, accidental- 
ly m.ade use of the term geography of plants ; and the same 
expression occurs in the fanciful but graceful work of Ber- 
nardin de St. Pierre, Etudes de la Nature. A scientific treat- 
ment of the subject began, however, only when tlie geography 
of plants was intimately associated with the study of the dis- 

* On the pbysiognomy of plants, see Humboldt, Ansichten der Natur, 
bd. ii., s. 1-125. 

t ^ina Dialogus. Opuscula, Basil., 1556, p. 53, 54. A very beauti- 
ful geography of the plants of Mount ^tna has recently been published 
by Philippi. See Linncea, 1832. s. 733. 



348 COSMOS. 

tribution of heat over the surface of the earth, and when the 
arrangement of vegetable forms in natural families admitted 
of a numerical estimate being made of the different forms 
which increase or decrease as we recede from the equator to- 
M^ard the poles, and of the relations in which, in different parts 
of the earth, each family stood with reference to the whole 
mass of phanerogamic indigenous plants of the same region. 
I consider it a happy circumstance that, at the time during 
which I devoted my attention almost exclusively to botanical 
pursuits, I was led by the aspect of the grand and strongly 
characterized features of tropical scenery to direct my investi- 
gations tov/ard these subjects. 

The study of the geographical distribution of animals, re- 
garding which Bulibn hrst advanced general, and, in most 
instances, very correct views, has been considerably aided in 
its advance by the progress made in modern times in the 
geography of plants. The curves of the isothermal lines, and 
more especially those of the isochimenal lines, correspond with 
the limits which are seldom passed by certain species of plants, 
and of animals which do not wander far from their fixed hab- 
itation, either with respect to elevation or latitude.* The 

* [The following valuable remarks by Professor Forbes, on the cor- 
respondence existing between the distribution of existing faunas and 
floras of the Bi'itish Islands, and the geological changes that have affect- 
ed their ai-ea, will be read with much intei-est; they have been copied, 
by the author's permission, from the Survey Report, p. 16 : 

" If the view I have put forward respecting the origin of the flora of 
the British mountains be true — and every geological and botanical prob- 
ability, so far as the area is concerned, favors it — then must we endeav- 
or to find some more plausible cause than any yet shown for the pres- 
ence of numerous species of jilants, and of some animals, on the higher 
parts of Alpine ranges in Europe and Asia, specifically identical with 
animals and plants indigenous in regions very far north, and not found 
in the intermediate lowlands. Tournefort first remarked, and Hum- 
boldt, the great organizer of the science of natural history geography, 
demonstrated, that zones of elevation on mountains correspond to par 
allels of latitude, the higher with the more northern or southern, as the 
case might be. It is well known that this correspondence is recogniz- 
ed in the ^enevaX fades of the flora and fauna, dependent on generic 
con'espondences, specific representatives, and, in some cases, specific 
identities. But when announcing and illustrating the law that climatal 
zones of animal and vegetable life are mutually repeated or represented 
by elevation and latitude, naturalists have not hitherto sufliiciently (if 
at all) distinguished between the evidence of that law, as exhibited by 
representative species and by identical. In reality, the former essen- 
tially depend on the law, the latter being an accident not necessarily 
dependent upon it, and which has hitherto not been accounted for. In 
the case of the Alpine flora of Britain, the evidence of the activity of 
thp lavg, and the influence of the accident, are inseparable, the law ho- 



FLORAS OF DIFFERENT COUNTRIES. 349 

elk, for instance, lives in the Scandinavian peninsula, almost 
ten degrees further north than in the interior of Siberia, where 
the line of equal winter temperature is so remarkably concave, 
Plants migrate in the germ ; and, in the case of many species, 
the seeds are furnished with organs adapting them to be con- 
veyed to a distance through the air. When once they have 
taken root, they become dependent on the soil and on the 
strata of air surrounding them. Animals, on the contrary, can 
at pleasure migrate from the equator toward the poles ; and 
this they can more especially do where the isothermal lines 
are much inflected, and where hot summers succeed a great 
degree of winter cold. The royal tiger, which in no respect 
diiiers from the Bengal species, penetrates every summer into 

ing maintained by a transported flora, for the transmission of which I 
have shown we can not account by an appeal to unquestionable geo- 
logical events. In the case of the Alps and Carpathians, and some other 
mountain I'anges, we find the law maintained partly by a representa- 
tive flora, special in its region, i. e., by specific centers of their own, 
and partly by an assemblage more or less limited in the several ranges 
of identical species, these latter iu several cases so numerous that or- 
dinary modes of transpoi'tation now in action can no more account for 
their presence than they can for the presence of a Norwegian flora on 
the British mountains. Now I am prepared to maintain that the same 
means which introduced a sub- Arctic (now mountain) flora into Britain, 
acting at the same epoch, originated the identity, as far as it goes, of 
the Alpine floras of Middle Europe and Central Asia; for, now that we 
know the vast area swept by the glacial sea, including almost the whole 
of Central and Northern Europe, and belted by land, since greatly up- 
lifted, which then presented to the water's edge those climatal condi- 
tions for which a sub-Arctic flora — destined to become Alpine — was 
specially organized, the difficulty of deriving such a flora from its par- 
ent north, and of difi'iising it over the snowy hills bounding this glacial 
ocean, vanishes, and the presence of identical species at such distant 
points remain no longer a mystery. Moreover, when we consider that 
the greater part of the northern hemisphere was under such climatal 
conditions during the epoch referred to, the undoubted evidences of 
which have been made known in Europe by numerous British and 
Continental observers, on the bounds of Asia by Sir Roderick Murchi- 
sou, in America by Mr. Lyell, Mr. Logan, Captain Bayfield, and oth- 
ei's, and that the botanical (and zoological as well) region, essentially 
northern and Alpine, designated by Professor Schouw that * of saxi- 
frages and mosses,' and first in his classification, exists now only on 
the flanks of the great area which suflered such conditions ; and that, 
though similar conditions reappear, the relationship of Alpine and Ai'ctic 
vegetation in the southern hemisphere, with that iu the northern, is 
entirely maintained by representative, and not by identical species (the 
representative, too, being iu great part generic, and not specific), the 
general truth of my explanation of Alpine floras, including identical 
species, becomes so strong, that the view proposed acquires fair claims 
to be ranked as a theory, and not considered merely a convenient or 
bold hypothesis."] — Tr. 



350 COSMOS. 

the north of Asia as far as the latitudes of BerHii and Ham- 
burg, a fact of which Ehrenberg and myself have; spoken in 
other works.* 

The grouping or association of different vegetable species, 
to which we are accustomed to apply the term Floras, do not 
appear to me, from what I have observed in different portions 
of the earth's surface, to manifest such a predominance of in- 
dividual families as to j ustify us in marking the geographical 
distinctions between the regions of the Umbellatee, of the So- 
lidaginse, of the Labiatse, or the Scitaminese. With reference 
to this subject, my views differ from those of several of my 
friends, who rank among the most distinguished of the bota- 
nists of Germany. The character of the floras of the elevated 
plateaux of Mexico, New Granada, and Quito, of European 
Russia, and of Northern Asia, consists, in my opinion, not so 
much in the relatively larger number of the species presented 
by one or two natural families, as in the more complicated 
relations of the coexistence of many families, and in the rela- 
tive numerical value of their species. The Graminese and 
the Cyperacese undoubtedly predominate in meadow lands 
and steppes, as do Coniferee, Cupuliferae, and BetulineaB in our 
northern woods ; but this predominance of certain forms is 
only apparent, and owing to the aspect imparted by the social 
plants. The north of Europe, and that portion of Siberia 
which is situated to the north of the Altai Mountains, have 
no greater right to the appellation of a region of GramineEe 
and Coniferse than have the boundless llanos between the 
Orinoco and the mountain chain of Caraccas, or the pine for- 
ests of Mexico. It is the coexistence of forms which may par- 
tially replace each other, and their relative numbers and as- 
sociation, which give rise either to the general impression of 
luxuriance and diversity, or of poverty and uniformity in the 
contemplation of the vegetable world. 

In this fragmentary sketch of the phenomena of organiza- 
tion, I have ascended from the simplest cellf — the first mani- 
festation of life — progressively to higher structures. " The 

* Ehrenberg, in the Annales des Sciences Naturelles, t. xxi., p. 387 
412; Humboldt, Asie Centrale, t. i., p. 339-342, and t. iii., p. .96-101 

t Schleiden, Ueber die Enhvicklungsiceise der Pfianzenzellen, in Miil 
ler's Archiv fur Anatomic und Physiologic, 1838, s. 137-176; also his 
Grundzuge der wissenschnftlichen Botanik, th. i., s. 191, and th. ii., s 
11. Schwann, Mikroscopische Untersnchungcn ubcr die Uehereinstim- 
mting in der Struktur und dem Wachsthiim der Thiere und PJlanze?i, 
1839, s. 45, 220. Compare also, on similar propagation, .Toh. Miillei- 
Physiologic des Mcnschcn, 1840 th. ii., s. 614. 



MAN. 351 

association of mucous granules constitutes a definitely-formed 
cytoblast, around which a vesicular membrane forms a closed 
cell," this cell being either produced from another pre-existing 
cell,* or being due to a cellular formation, which, as in the 
case of the fermentation-fungus, is concealed in the obscurity 
of some unknown chemical process.! But in a work like the 
present w^e can venture on no more than an allusion to the 
mysteries that involve the question of modes of origin ; the 
geography of animal and vegetable organisms must limit itself 
to the consideration of germs already developed, of their hab- 
itation and transplantation, either by voluntary or involuntary 
migrations, their numerical relation, and their distribution 
over the surface of the earth. 

The general picture of nature which I have endeavored to 
delineate would be incomplete if I did not venture to trace a 
few of the most marked features of the human race, considered 
with reference to physical gradations — to the geographical 
distribution of cotemporaneous types — to the influence exer- 
cised upon man by the forces of nature, and the reciprocal, 
although weaker action which he in his turn exercises on 
these natural forces. Dependent, although in a lesser degree 
than plants and animals, on the soil, and on the meteorolog- 
ical processes of the atmosphere with which he is surrounded 
— escaping more readily from the control of natural forces, by 
activity of mind and the advance of intellectual cultivation, 
no less than by his wonderful capacity of adapting himself to 
all climates — man every where becomes most essentially asso- 
ciated with terrestrial life. It is by these relations that the 
obscure and much-contested problem of the possibility of one 
common descent enters into the sphere embraced by a general 
physical cosmography. The investigation of this problem will 
impart a nobler, and, if I may so express myself, more purely 
human interest to the closing pages of this section of my work. 

The vast domain of language, in whose varied structure we 
see mysteriously reflected the destinies of nations, is most inti- 
mately associated with the affinity of races ; and what even 
slight differences of races may effect is strikingly manifested 
in the history of the Hellenic nations in the zenith of their 
intellectual cultivation. The most important questions of the 
civilization of mankind are connected with the ideas of races, 

* Schleiden, Grundzuge der wissenschafilicken Botanik, 1842, th. i., 
6. 192-197. 

t [Oil cellular formation, see Henfrey's Outlines of Structural and 
Physiological Botany, op. cit., p. 16-22.] — Tr. 



352 COSMOS. 

community of language, and adherence to one original direc- 
tion of the intellectual and moral faculties. 

As long as attention was directed solely to the extremes in 
varieties of color and of form, and to the vividness of the first 
impression of the senses, the observer was naturally disposed 
to regard races rather as originally different species than as 
mere varieties. The permanence of certain types* in the midst 
of the most hostile influences, especially of climate, appeared 
to favor such a view, notwithstanding the shortness of the in- 
terval of time from which the historical evidence was derived. 
In my opinion, however, more powerful reasons can be ad- 
vanced in support of the theory of the unity of the human 
race, as, for instance, in the many intermediate gradations! 
in the color of the skin and in the form of the skull, which 
have been made known to us in recent times by the rapid prog- 
ress of geographical knowledge — the analogies presented by 
the varieties in the species of many wild and domesticated ani- 
mals — and the more correct observations collected regarding 
the limits of fecundity in hybrids. | The greater number of 
the contrasts which were formerly supposed to exist, have dis- 
appeared before the laborious researches of Tiedemann on the 
brain of negroes and of Europeans, and the anatomical iiives- 

* Tacitus, in his speculations on the inhabitants of Britain (Agricola, 
cap. ii.), distinguishes with much judgment between that which may 
be owing to the local climatic relations, and that which, in the imrai- 
gi'ating races, may be owing to the michangeable influence of a hered- 
itary and transmitted type. " Britanniam qui mortales initio colueiaint, 
indigenai an advecti, ut inter barbaros, parum compertum. Habitus 
corpons varii, atque ex eo ai'gumeuta ; namque rutilae Caledoniam hab- 
itantium coma;, magni artus Germanicam originem adseverant. Silu 
rum colorati vultus et torti plerumque crines, etposita contra Hispania, 
Iberos veteres trajecisse, easque cedes occupasse fidem faciunt: proxi- 
mi Gallis, et similes sunt: seu durante originis vi ; seu procurrentibus 
in diversa terris, positio coeli corporibus habitum dedit." Regarding 
the persistency of types of conformation in the hot and cold regions of 
the earth, and in the mountainous districts of the New Continent, see 
my Relation Historique, t. i., p. 498, 503, and t. ii,, p. 572, 574. 

t On the Amei'icau races generally, see the magnificent work of 
Samuel George Morton, entitled Crania Americana, 1839, p. 6'2, 8G ; 
and on the skulls brought by Pentland from the highlands of Titicaca, 
see the Dublin Journal of Medical and Chemical Science, vol. v., 1834, 
p. 475 ; also Alcide d'Orbigny, Vhommc AyiUricain consid6r6 sous ses 
rapports Physiol, et Mor., 1839, p. 221 ; and the work by Prince Maxi- 
milian of Wied, which is well worthy of notice for the admirable ethno 
graphical remarks in which it abounds, entitled Reise in das Innere von 
Nordamerika (1839). 

X Rudolph Wagner, Ueher Dlaidlinge und Bastarderzeugnng, in his 
notes to the German translation of Prichard's Physical History of Man- 
kind, vol. i., p. 138-150. 



RACES. 353 

tigalions of Vrolik and Weber on the form of the pelvis. On 
comparing the dark-colored African nations, on whose physical 
history the admirable work of Prichard has thrown so much 
light, with the races inhabiting the islands of the South-In- 
dian and West- Australian archipelago, and with the Papuas 
and Alfourous (Haroforas, Endamenes), we see that a black 
skin, woolly hair, and a negro-like cast of countenance are not 
necessarily connected together.* So long as only a small por- 
tion of the earth was known to the Western nations, partial 
views necessarily predominated, and tropical heat and a black 
skin consequently appeared inseparable. " The Ethiopians," 
said the ancient tragic poet Theodectes of Phaselis,! " are 
colored by the near sun-god in his course with a sooty luster, 
and their hair is dried and crisped with the heat of his rays." 
The campaigns of Alexander, which gave rise to so many new 
ideas regarding physical geography, likewise first excited a dis- 
cussion on the problematical influence of climate on races. 
" Families of animals and plants," writes one of the greatest 
anatomists of the day, Johannes Miiller, in his noble and com- 
prehensive work, Physiologie cles Menschen, " undergo, within 
certain limitations peculiar to the different races and species, 
various modifications in their distribution over the surface of 
the earth, propagating these variations as organic types of spe- 
cies. $ The present races of animals have been produced by 

* Prichard, op. cit., vol. ii., p. 324. 

t Onesicritus, in Strabo, xv., p. 690, 695, Casaub. Welcker, Grie- 
chische Tragodien, abth. iii., s. 1078, conjectures that the vei'ses of 
Theodectes, cited by Strabo, are taken from a lost tragedy, which prob- 
ably bore the title of " Memnon." 

X [In illustration of this, the conclusions of Professor Edward Forbes 
respecting the origin and diffusion of the British flora may be cited. 
See the Survey Memoir already quoted, On the Connection between the 
Distribution of the existing Fauna and Flora of the British Islands, &c., 
p. 65. *' 1. The flora and fauna, terrestrial and marine, of the British 
islands and seas, have originated, so far as that area is concerned, since 
the meioceue epoch. 2. The assemblages of animals and plants com- 
posing that fauna and flora did not appear in the area they now inhabit 
simultaneously, but at several distinct points in time. 3. Both the fauna 
and flora of the British islands and seas are composed partly of species 
which, either permanently or for a time, appeared in that area before 
the glacial epoch ; partly of such as inhabited it during that epoch ; and 
in great part of those which did not appear there until afterward, and 
whose appearance on the earth was coeval with the elevation of the 
bed of the glacial sea and the consequent climatal changes. 4. The 
greater part of the terrestrial animals and flowering plants now inhab- 
iting the Bx'itish islands are members of specific centers beyond their 
area, and have migrated to it over continuous land before, duriag, or 
after the glacial epoch. 5. The climatal conditions of the area under 



354 COSMOS. 

the combined action of many different internal as well as ex- 
ternal conditions, the nature of which can not in all cases be 
defined, the most striking varieties being found in those fami- 
lies which are capable of the greatest distribution over the sur- 
face of the earth. The difierent races of mankind are forms 
of one sole species, by the union of two of whose members 
descendants are propagated. They are not different species 
of a genus, since in that case their hybrid descendants would 
remain unfruitful. But whether the human races have de- 
scended from several primitive races of men, or from one alone, 
is a question that can not be determined from experience."* 

Geographical investigations regarding the ancient seat, the 
so-called cradle of the human race, are not devoid of a myth- 

discussiou, and north, east, and west of it, were severer during the gla 
cial epoch, when a gi'eat part of the space now occupied by tlie British 
isles was under water, than they ai'e now or were before ; but there is 
good reason to believe that, so far from those conditions having contin- 
ued severe, or having gradually diminished in severity southward of 
Britain, the cold region of tlie glacial epoch came directly into contact 
with a region of more southern and thermal character than that in which 
the most southern beds of glacial drift are now to be met with. 6. This 
state of things did not materially differ from that now existing, under 
corresponding latitudes, in the North American, Atlantic, and Arctic 
seas, and on their bounding shores. 7. The Alpine floras of Europe 
and Asia, so far as they are identical with the flora of the Arctic and 
sub-Arctic zones of the Old World, are fragments of a flora which was 
diffused from the north, either by means of transport not now in action 
3n the temperate coasts of Europe, or over continuous land which no 
^onger exists. The deep sea fiiuna is in like manner a fragment of the 
general glacial fauna. 8. The floras of the islands of the Atlantic re- 
gion, between the Gulf-weed Bank and the Old World, are fragments 
of the great Mediterranean flora, anciently diffused over a land consti- 
tuted out of the upheaved and never again submerged bed of the (shal- 
low) Meiocene Sea. This great flora, in the epoch anterior to, and 
probably, in part, during the glacial period, had a greater extension 
northward than it now presents. 9. The termination of the glacial 
epoch in Europe was marked by a recession of an Arctic fauna and flora 
northward, and of a fauna and flora of the Mediterranean type south- 
ward ; and in the interspace thus produced there appeared on land the 
Germanic fauna and flora, and in the sea that fauna termed Celtic. 
10. The causes which thus preceded the appearance of a new assem- 
blage of organized beings were the destruction of many species of ani- 
mals, and probably also of plants, either forms of extremely local dis- 
tribution, or such as were not capable of enduring many changes of con- 
ditions — species, in short, with very limited capacity for horizontal or 
vertical diffusion. 11. All the changes before, during, and after the 
glacial epoch appear to have been gradual, and not sudden, so that no 
marked line of demarkation can be drawn between the creatures in- 
habiting the same element and the same locality during two proximate 
periods."] — Tr. 

* Job. M\ji[\er,Physiologie des Mensehen, bd. ii., s. 768. 



RACES. 355 

ical character, '* We do not know,'' says Wilhelm von Hum- 
boldt, in an unpublished work On the Varieties of Languages 
and Nations, " either from history or from authentic tradition, 
any period of time in which the human race has not been 
divided into social groups. Whether the gregarious condition 
was original, or of subsequent occurrence, we have no historic 
evidence to show. The separate mythical relations found to 
exist independently of one another in different parts of the 
earth, appear to refute the first hypothesis, and concur in 
ascribing the generation of the whole human race to tlie union 
of one pair. The general prevalence of this myth has caused 
it to be regarded as a traditionary record transmitted from 
the primitive man to his descendants. But this very circum- 
stance seems rather to prove that it has no historical foiuida- 
tion, but has simply arisen from an identity in the mode of 
intellectual conception, which has CA^ery where led man to 
adopt the same conclusion regarding identical phenomena ; in 
the same manner as many myths have doubtlessly arisen, not 
from any historical connection existing between them, but 
rather from an identity in human thought and imagination. 
Another evidence in favor of the purely mythical nature of 
this belief is afforded by the fact that the first origin of man- 
kind — a phenomenon which is wholly beyond the sphere of 
experience — is explained in perfect conformity with existing 
views, being considered on the principle of the colonization of 
some desert island or remote mountainous valley at a period 
when mankind had already existed for thousands of years. It 
is in vain that we direct our thoughts to the solution of the 
great problem of the first origin, since man is too intimately 
associated with his own race and with the relations of time 
to conceive of the existence of an individual independently of 
a preceding generation and age. A solution of those difficult 
questions, which can not be determined by inductive vea5:oning 
or by experience — whether the belief in this presumed tradi- 
tional condition be actually based on historical evidence, or 
whether mankind inhabited the earth in gregarious associa- 
tions from the origin of the race — can not, therefore, be de- 
termined from philological data, and yet its elucidation ought 
not to be sought from other sources." 

The distribution of mankind is therefore only a distribution 
into varieties, which are commonly designated by the some- 
what indefinite term races. As in the vegetable kingdom, 
and in the natural history of birds and fishes, a classification 
into many small families is based on a surer foundation than 



356 (josMOS. 

where large sections are separated into a few but large divi- 
sions ; so it also appears to me, that in the determination of 
races a preference should be given to the establishment of 
small families of nations. Whether we adopt the old classi- 
fication of my master, Blumenbach, and a.dmit Jive races (the 
Caucasian, Mongolian, American, Ethiopian, and Malayan), 
or that of Prichard, into seve7i races* (the Iranian, Turanian, 
American, Hottentots and Bushmen, Negroes, Papuas, and 
Alfourous), we fail to recognize any typical sharpness of def- 
inition, ^or any general or well-established principle in the di- 
vision of these groups. The extremes of form and color are 
certainly separated, but without regard to the races, which 
can not be included in any of these classes, and which have 
been alternately termed Scythian and Allophyllic. Iranian is 
certainl}* a less objectionable term for the European nations 
than Caucasian ; but it may be maintained generally that 
geographical denominations are very vague when used to ex- 
press the points of departure of races, more especially where 
the country which has given its name to the race, as, for in- 
stance, Turau (Mawerannahr), has been inhabited at differ- 
ent periods! by Indo-Germanic and Finnish, and not by Mon- 
golian tribes. 

* Prichard, op. cit., vol. i., p. 247. 

t The late arrival of tlie Turkish and Mongolian tribes on the Oxua 
and on the Kirghis Steppes is opposed to the hypothesis of Niebuhr, 
accordhig to which the Scythians of Herodotus and Hippocrates were 
Mongolians. It seems far more probable that the Scythians (Scoloti) 
should be referred to the Indo-Germanic Massage t<e (Alani). The 
Mongolian, true Tartars (the latter term was afterward falsely given to 
purely Turkish tribes in Russia and Sibei'ia), were settled, at that pe- 
riod, far in the eastern part of Asia. See my Asie Centrale, t. i., p. 239, 
400 ; Examen Critique de VHistoire de la Giogr., th. ii., p. 320. A dis- 
tinguished philologist, Professor Buschmann, calls attention to the cir- 
cumstance that the poet Firdousi, in his half-mythical prefatory remarks 
in \\ie Schahnameh, mentions "a fortress of the Alani'' on the sea-shore, 
in which Selm took refuge, this prince being the eldest son of the 
King Feriduu, who in all probability lived two hundred years before 
Cyrus. The Kirghis of the Scythian steppe were originally a E'innish 
tribe ; their three hordes probably constitute in the present day the 
most numerous nomadic nation, and their tribe dwelt, in the sixteenth 
century, in the same steppe in which I have myself seen them. The 
Byzantine Menander (p. 380-382, ed. Nieb.) expressly states that the 
Chacan of the Turks (Thu-Khiu), in 5G9, made a present of a Kirghis 
slave to Zemarchus, the embassador of Justinian II. ; he terms her a 
X^PXk ) tiiid. we find in Abulgasi {Historia MongoJorum el Tataroruni) 
that the Kirghis are called Kirkiz. Similarity of manners, where the 
nature of the country determines the i)rincipal characteristics, is a very 
uncertain evidence of identity of race. The life of the steppes pro- 
duces among the Turks (Ti Tukiu), the Baschkirs (Fins), the Kirghis, 



LANGUAGE. 357 

Larguages, as intellectual creations of man, and as closely- 
interwoven with the development of mind, are, independently 
of the national form which they exhibit, of the greatest im- 
portance in the recognition of similarities or differences in 
races. This importance is especially owing to the clew which 
a community of descent affords in treading that mysterious 
^abyrinth in which the connection of physical powers and in- 
tellectual forces manifests itself in a thousand different forms. 
The brilliant progress made within the last half century, in 
Germany, in philosophical philology, has greatly facilitated 
our investigations into the national character* of languages 
and the influence exercised by descent. But here, as in all 
domams of ideal speculation, the dangers of deception are 
closely linked to the rich and certain profit to be derived. 

Positive ethnographical studies, based on a thorough knowl- 
edge of history, teach us that much caution should be applied 
in entering into these comparisons of nations, and of the lan- 
guages employed by them at certain epochs. Subjection, 
long association, the influence of a foreign religion, the blend- 
ing of races, even when only including a small number of the 
more influential and cultivated of the immigrating tribes, 
have produced, in both continents, similarly recurring phenom- 
ena ; as, for instance, in introducing totally different families 
of languages among one and the same race, and idioms, having 
one common root, among nations of the most different origin. 
Great Asiatic conquerors have exercised the most powerful 
influence on phenomena of this kind. 

But language is a part and parcel of the history of the de- 
velopment of mind ; and, however happily the human intel- 
lect, under the most dissimilar physical conditions, may unfet- 
tered pursue a self-chosen track, and strive to free itself from 
the dominion of terrestrial influences, this emancipation is 
never perfect. There ever remains, in the natural capacities 
of the mind, a trace of something that has been derived from 
the influences of race or of cUmate, whether they be associated 
with a land gladdened by cloudless azure skies, or with the 
vapory atmosphere of an insular region. As, therefore, rich- 
ness and grace of language are unfolded from the most luxu- 

the Torgodi and Dsungari (Mongoliaus), the same habits of nomadic 
Hfe, and the same use of felt tents, carried on wagons and pitched 
among herds of cattle. 

* Wilhelm von Humboldt, Ueher die Verschiedenheit der menschlichen 
Sprachbaues, in his great work Ueher die KawiSprache auf der Insd 
Java, bd. i., s. xxi., xlviii., and ccxiv. 



Sbb COSMOS. 

riant depths of thought, we have been unwiUing wholly to 
disregard the bond which so closely links together the physical 
world with the sphere of intellect and of the feelings by de- 
priving this general picture of nature of those brighter lights 
and tints which may be borrowed from considerations, however 
slightly indicated, of the relations existing between races and 
languages. 

While we maintain the unity of the human species, we at 
the same time repel the depressing assumption of superior 
and inferior races of men.^ There Tire nations more sus- 
ceptible of cultivation, more highly civilized, more ennobled 
by mental cultivation than others, but none in themselves no- 
bler than others. All are in like degree designed for freedom ; 
a freedom which, in the ruder conditions of society, belongs 
only to the individual, but which, in social states enjoying po- 
litical institutions, appertains as a right to the whole body 
of the community. " If we would indicate an idea which, 
throughout the whole course of history, has ever more and 
more widely extended its empire, or which, more than any 
other, testifies to the much-contested and still more decidedly 
misunderstood perfectibility of the whole human race, it is 
that of establishing our common humanity — of striving to re- 
move the barriers which prejudice and limited views of every 
kind have erected among men, and to treat all mankind, with- 
out reference to religion, nation, or color, as one fraternity, one 
great community, fitted for the attainment of one object, the 
unrestrained development of the physical powers. This is the 
ultimate and highest aim of society, identical with the direc- 
tion implanted by nature in the mind of